"The Big Two don't like Rick's work. It's as simple as that. In the last ten years, he's gone from being able to work steadily at Marvel Comics and DC Comics to not being able to get hired. They just won't give him the time of day.
Rick is one of the most accomplished artists I've ever worked with. He's known primarily for winning Eisners doing Batman & Robin Adventures where Rick himself says that he was paid to draw like Bruce Timm. So, I think for a lot of people there is a sense that he's too cartoony, his style doesn't fit in with what the big two want; it's not sexy or flashy enough. He has a very distinct comic book style, he doesn't do photo-realistic. Everything he draws, he can draw it. It's not light-boxing here.
I know at least one editor who went to great lengths to make sure he wouldn't work at one company and really set him up to fail and did so gleefully. Comics are like any other industry; there are wonderful people in it and there are crappy people in it."