After carefully reading your comic, and understanding your background, I am sorry to say that your approach to comic making is fundamentally wrong.
First off, you say that you make storyboards for animation. You do have skill in art and ink, and it shows well in your backgrounds and character design. However, your writing is very bland and gives little to no characterization. Why? Either this has something to do with the old pre-1990 style, however there's no reason why dialogue, characters and writing can't be interesting and meaningful with the space provided; so then it has to do with your personal skill with writing. And just because you know how to write for animation, that doesn't mean the same methods can carry over to comics with ease. Every kind of writing is different, and each has its own way of being presented, so each way needs time to be learned.
I'm still learning myself and I like to understand how each kind works. With now ten years of study in play-writing and novel writing, I realize that I have a long way to go before I say that I'm a master of comic making.
Believe me, I used to like reading the old comics too. However, now that I have ten years of writing experience behind me, I look back at a lot of them now and I realize that the writing in a lot of them are about telling, not showing. It told you how a person felt instead of showing it on the expression on their face or have it affect their actions. This wasn't always the case, but the more prominent comics were like this.
That's why comics strips have evolved from the classic comic strips to Graphic Novels they are today. There's more space involved now for pacing and story, and larger, more active panels to heighten drama, action, setting and emotion. The "ten page" depictions you speak of are usually well put together in order to make a scene resonate in your head, while the one page strips have a ton of content squeezed into just a few panels, which some people may like, but if not done well, it leaves much to be desired. Looking back, because of the lack of space, a lot of the old comics are very bland when it comes to the characterization and the meaningful dialogue department.
Next, you say that the decompression in comics is criticized often, but every medium has that to some extent. If we look back, the old comics strips were criticized as well by being called "childish" and "for kids". That's because they liked to hand-hold you the entire time, telling you everything when it should already be apparent through the story or dialogue. It's similar to what videogames are going through now.
Now comes your questions. You can publish anything here on Tapastic, vertical or horizontal. It has nothing to do with orientation. But then you ask, is your storytelling passe for younger readers? No.
It's passe for all readers.
Sorry to be harsh, but it is. Not only is it hard to read, it lacks the basics in writing and dialogue. It's all interjections and telling us what to see instead of just showing us through the art. Your characters explain everything instead of saying actual things people may say in their situations. True, all comics have a story to explain, but yours is neither smooth nor well spoken. If you were to write all what is written there in a full length book, it would be very difficult to get it published. I certainly wouldn't read it. I'm terribly sorry if this sounds mean, but it has to be said if you are to improve. You are a great artist, and your story has a great idea to it, but your writing and pacing needs to be worked on.
Speaking of pacing, Comics, no matter how old or young, have an automatic limitation placed on them when it comes to pacing. With animation or cinema, the pacing comes from how the picture is presented on screen, 1-to-1, which is controlled by the creators of the production. With comics however, because they rely on the eye of the reader and their personal ability to understand what is portrayed, everything, and I mean everything - the setting, sounds, action, speech - is up to the artist's skill to portray it on the page. It is the artist's job to make the understanding of the passage of time as easy as possible, thus the need for "ten pages" sometimes to display a scene instead of just one. You wouldn't squeeze twenty meaningful and plot-filled minutes of a movie into just two, would you? (unless you have the genius to do it)
And even if you were limited to just a few panels, you can definitely make the most of your space with proper thought bubble and speech balloon placement, and by not writing something that could just as easily be portrayed in the comic's art, e.g. how Johnny likes his eggs. Every scene should be representative of a moment in time, not a summary of it speeding by like a freight train.
And that's the beauty of the serial comic strips. You can take your time to build up suspense with every episode, giving some time to each character and to your story. If done right, it leaves you wanting more. If done wrong, it's a mess. So take that cartoonist's advice with a grain of salt. He has a lot more experience than you in the comic making department just like you have more experience in the storyboarding department.
