In no way am I trying to put you down, of course, I am just trying to help. So don't take any of what I say in a bad way. However, I feel like your replies are revealing some of the reasons why artists choose not to work with you.
1.) When you responded to people asking you to show examples of your work or samples of your writing skills, you don't provide anything. You don't show that you know how to provide these examples.
This just makes it seem as if you don't know what you're doing in terms of writing. Do you know how to write a script that would be suitable for an artist to use? Do you know how to create a treatment? Have you done your research on the genre that you want to work on and the medium you're trying to get into? None of your replies show that to me. If I was an artist I would be hesitant to work with someone that can't do these things. This is not to say that you can't, but I should be able to see that just from how you present yourself. There is no problem with asking questions and learning but you shouldn't be asking these questions and also asking people to risk their own time working with you.
Well, these situations are rarely ever fruitful. Have you looked up the comics that they requested a collab for? Often those collaborations don't go anywhere past maybe a sketch. The most cited reason for this is that the writer didn't have anything on hand. No scripts, no writing, not even an outline. Just a couple of ideas. You even admit to having experienced this yourself.
The reason they're "complaining" is because you're giving them nothing to work on and to be frank... You're kinda wasting their time. If you don't even have an outline for your story, what makes you different from any other person? Why should they put the time in for you if you aren't even willing to put the time in yourself?
You do bring up a point about not wanting to work on a script without a partner so they can have a say in it.
This sounds great on paper. But unless you're already an established writer with experience completing projects, this mentality won't work for you. When I said before about letting your artist take some control of the story, I mean in the sense that you should allow them to make changes to your story if need be. Here, for example:
My comic Cross (shameless plug if you're interested in reading it 
https://tapas.io/series/SC_Cross) and all of Sinical Comics is a collaboration between me and my artist. I had originally written Cross by myself without any input and when my artist got on board with the project it made drastic changes from the original script. One notable change that happened while making Cross was the setting of Chapter 0.
It's set in a dark and eerie forest with towering trees, and large sprouts of vegetation with the only light being from the moon.
It has somber purple hues that give it a depressing feel. This wasn't in the script that this was based on.
In the script, I had written that it was a blood moon with shades of red illuminating a forest, making it look more like Hell than Earth.
(It looks really bad here because this was the result of me putting a red filter over the image above just as a visual representation.)
The reason why we did this change was that my artist felt that the red would make certain scenes not stick out as much. For example:
Over the purple colors, the orange of their eyes revealing a more bestial side of them becomes much more jarring. It sticks out way more and is much more striking.
Compare that to had we use the original color of red
Again, not amazing visuals since they weren't made to have red but the point still stands. The red would've drawn attention away from what I was trying to show. What truly convinced me though was this panel
CW FOR BLOOD CW FOR BLOOD
CW FOR BLOOD CW FOR BLOOD
CW FOR BLOOD CW FOR BLOOD
CW FOR BLOOD CW FOR BLOOD
CW FOR BLOOD CW FOR BLOOD
CW FOR BLOOD CW FOR BLOOD
Here we see Jesse (the MC) grieving for his father. The original purple makes the blood on Jesse and his father so much more jarring and shocking. The blood acts as a way for us to see the Innocence of this boy be taken away in an instant. We also can take advantage of the somber purple to show the orange hue around Jesse, showing that this emotional toll is starting to unlock his bestial nature. However, in the red, the blood is not as shocking and the orange aura kinda blends in with the background. The red would be good to show his anger in this scene but that's not what I'm trying to convey. He isn't just angry in this scene, he's sad, confused, and unsure of where to go. He's not thinking about getting revenge or even fleeing the scene to keep himself safe. The only thing he can think of at this moment is spending his final moments with his father.
Of course, the red tint looks like garbage here but it's my way of showing you how collaboration works. It's not you two building a story together, it's both of you playing to your advantage. My artist isn't a writer, why should we pretend he is? Why should help me write the script when I easily can do it myself? My artist is an artist, end of the day. His strength is making a visual story. This scene was made 100x better than I originally planned just because the artist knew his strengths. He didn't help me plan the story or write the script but he improved what he was given drastically because he understood what was being conveyed through my script and felt there was a way to make what I'm trying to convey even better. That's true synergy. That's a collaboration.
My issue here is that you don't understand that part. In my reply, I said there were questions you need to ask yourself. One of these questions was
When I asked this, I was not saying "what other reward you are giving them?" I'm asking what do you have to offer? What are you doing that the artist can't? If the artist is both working on the art and also on the script, why should they work with you? if they can do both, then they have the means to make their own comic without you.
You did answer this question with
This is my answer: My strengths and my passion. I like to say I'm a good writer. I know how to write a decent script and I'm very good at conveying my ideas on paper. My artist is good at taking what I write down and using that to create his own version of my story within the visual medium of comics. My style of writing, which was inspired by horror and action like Hellsing and Baki meshes with his art style which was inspired by magical girls and romance, like Steven Universe and K-Dramas creating a distinct voice within Cross that can only really exist between the two of us.
And despite what people believe, money isn't all you need. You can pay 100s of dollars and people still won't take you up on your offer simply because a comic is a huge commitment that you're asking them to do. If you aren't presenting your strengths and your knowledge, then you're just another "idea guy" that posts on the forums every day. Even if you did offer pay, it just wouldn't be worth it if you don't have anything else to offer.
2.) In your response to my previous message, I brought up how you need to be open to criticism.
To which you responded with this.
And while I am not trying to accuse you of lying, I don't get the feeling you understand exactly what they're asking for, and I don't think you're trying to understand. Especially since you've replied to many of the messages posted in this thread in a very dismissive way, saying that they think you're just entitled. Now, I cannot make a judgment like that because I don't know you but you do have a few examples in your replies where you show some levels of entitlement
This just comes across as you complaining. As if it's unfair that the other writers are getting something you aren't getting. As if you're entitled to an artist because "well that writer over there got one!". I'm sorry but that's not how this works.
This is your problem. As I said in my first point, you're not making yourself stand out. Not only do these collabs don't work as much as you think they do, but even if they did you're just trusting that some artist is going to pick you out of the crowd just because you want them to. If you want an artist, you need to stick out and show off what you have. This mindset seems somewhat lazy to me as if you don't want to put in the effort as a writer because other writers aren't. If you want to find an artist, work for it. Put in the time to do research and write out your story. I'll tell you right now? Artists don't want to work on your story for you, they want to work with you on your story and improve what you already have. As the writer, you must provide a base for them to work with.
When people do end up leaving, it's because they never were that dedicated in the first place, and artists saw that. You need to understand that it requires a lot of dedication to get a comic from a simple idea to being published on Tapas. It took Cross 2 years to come out and then we had to reset and redo it because we weren't happy with the first product and the Redux version took another year to come out. Do you think the ones who quit would've stuck through years of working on the same project and not quit if the project didn't get the views they wanted? Or maybe if the comic turned out bad and they had to redo it? Or if they had to go through the very tedious stage of editing and revising? Probably not.
Another question, and I think was the most important in my last reply to you
To which you responded with
And this, no offense at all, is the most revealing part of why you aren't getting an artist. Dedication is not something you need to intentionally show someone. You do it through how you act. By working on your story, doing your research, and showing that you're in this for the long haul. Show that you're passionate by the way you talk about your story. Do you find discussing your story more of a business meeting, where you're pitching an idea to someone to hopefully win their favor, or is it a genuine excitement from developing a world full of interesting characters, events, and plot? Because how I see it? It's the former. You haven't presented your ideas that make me feel like you're excited to tell this story. I don't feel that you need to tell a story: It just kinda feels as if you want to make a product.
I do not feel that you are passionate or dedicated in a way that makes artists want to work with you. Comics are a huge commitment that requires possibly years of someone's time and you're simply asking for a stranger to give you the benefit of the doubt. If you need to tell artists that you're worth it, then you're failing at showing that you are. I'm not saying you should quit but the opposite. I want you to find an artist, I want you to prove me and everyone else wrong. Don't tell me that you want to make a comic, everyone at some point has. Show me you want to. Show me the journal full of notes on all of your characters and dumb lore about them that will never come out in your story, show me your plot you spent months developing and honing. Show me the 30th draft you made of the first chapter because "It's just not perfect enough". Artists don't want ideas, they want passion and you just gotta show it.
This was way longer than I intended it to be. Like WAYYYY longer. And I'm just going to say sorry for any spelling mistakes. Please don't take this as me trashing you or seeing you as inferior because I don't! I do hope you find someone and I hope that in the future I'll come across your comic and see how much you grow as a writer!
Best of luck to ya! 
