Why do writers change companies?

This is just a bit of a question really, but why do writers always seem to go from company to company.

I'll use Morrison for example, he went from DC/Vertigo to Marvel for a time to do New X-Men, then returned to DC...and now I have no idea what he's doing aside for hiding in his Loony cave writing Multiversity....or something.

Same with writers for non comics: Greg Weisman went from Disney with Gargoyles to...whoever did W.I.T.C.H, to Sony (?) for Spectacular Spiderman to Cartoon Network/Warner for Young Justice and now is back at Disney for Rebels, all while also doing individual episodes for shows like The Batman, Brave and the Bold, Transformers Prime, Ben 10 and Legion of Superheroes

Paul Dini also went from Warner/DC/Whatever to DC proper, to Marvel to work on Ultimate Spiderman, yet also worked on Arkham City and that Tower Prep thing that Cartoon Network had.

Is their a limit of how many times a writer can do this? This isn't even going into how many writers do work for two companies, like Gail Simone for example with Red Sonja, Batgirl and The Movement.

Money

Money.

These. And, I'd imagine they want a chance to write characters from other companies for a change.

I mean, they're writing the same characters sometimes for years on end. I know I'd want a chance to write something new.

Maybe they just like to try different things, and when offered a good opportunity to do something at another company, it could be worth going for.

Possibly, but a little extra money gives them that extra motivation.

Money, better work environment/no exclusive contracts, wanting to own your work if you go to an independent publisher.

BB

They get to work with different characters that they grew up reading and when they work with independents, they have more creative control.

Grant Morrison is currently working on a Wonder Woman book

Greg Weisman actually did write comics. He wrote Captain Atom and created the "General Eiling" character.

Writers are writers, I don't think any writer just says "hey, I just want to write comics forever" They like to write so they will do it for any medium and I am sure getting paid for it has to do with it.

The examples you gave were all because of money except the Morrison one.He went to Marvel because he had an idea and wanted to write the X-Men.But most of the times these days writers change companies because of money and nothing else.

Same reason anyone changes jobs, money, benefits, job security.

Isn't Grant also doing that Wonder Woman book? I think it's called The trial of Diana Prince or something like that.

Why does anyone change jobs?

Creative people need changes and new challenges.