Lissen up, son, because I'm only going to say it once: ARTISTS CAN'T WRITE. Well, not exactly true: there's Jack Kirby, Eisner, and Jim Starlin and...oh yeah...NOBODY ELSE.
I think that's way too sweeping a generalization. There are plenty more artists who turned to writing and did at least a decent job at it. Just off the top of my head:
* Karl Kesel (Post-crisis, but still one of the best writers to work on Superman, IMO);
* George Perez;
* Frank Miller (I understand that people have problems with the
kind of stuff he writes, and disagree with his usage of established characters, but I don't see how you can deny his ability);
Even Jurgens and Ordway aren't bad writers, IMO -- though the former isn't as good as he seems to think he is.
I think the real lesson here is that artists
should not be automatically presumed to make good writers. They should have to prove themselves to the fans (and to the editors), just like anybody else.