The following comment from this interview with Gears of War 3 writer Karen Traviss explains a lot.
I don’t read novels. I’m a novelist, but I don’t read. I don’t like reading. I love comics. I love reading comics. I can still read comics and write, just about… But I come from a TV background.
The single most important thing anyone can do to be a better writer is to read, and specifically to read lots of different kinds of things. But if you want to write truly atrocious stuff like Gears of War 3, by all means stick to comic books and television.