I've personally do not like working with others. It's not that I can't, it's just that so far, everyone I've worked with has either been too busy to keep working, has too many opposing ideas, doesn't like the ideas in the end, or just doesn't contribute their own.
For example, I've thought of an amazing idea of a series that has a great concept, but it needed some polishing. So I talk with the "co-author" about it and he helps with the polishing by asking questions of how this or why that. Which was really helpful, so the idea itself is really close to coming to fruition. I just needed to get better at art in order to deliver, or get some help. So I call upon the same friend to get some designs done, and he agrees. I go nuts and design the main character, the main weapon type, and even the uniforms. When we meet again, he says he didn't like the design of any of it. I ask why, but he doesn't give a definite answer. So I ask what he's come up with. Bubkiss. Even after more brainstorming, we get stuck on an important design issue, and since I've practically designed everything, I ask if he can design this all important thing. He says sure. We meet again. BUBKISS! It got so frustrating that I've stopped talking with him about everything but the concepts. I've practically did everything anyways, with design, story, concept, tone, theme, etc., and I was all but ready to cut him off from the entire project.
And that's just with comics. Next there's writing. A ways back, a friend of mine wants to write something with me and we even brainstorm about the concept. We agree on some ideas, put together a storyline, and he jumps in to write the first few pages. Sadly, when he gets back to me, he's changed a lot of what we agreed on, some really important stuff that was key to the plot, and after I gave him some designs (which helps me with writing what the characters looks like) he doesn't end up liking anything I've put in (other than the concept) and dismisses it all. I've given up writing it with him and have decided to do my own thing with the idea later.
I'd list more, but until I find a decent partner, I really don't like to co-author anything.