Publishers employ writers who sell books. If fanboy wank like Geoff Johns and Joss Whedon is what's currently selling, then, the publishers will target more writers of the same caliber and lack of originality to sell more books.
If fans stop buying the tripe that Whedon, Loeb, and the like hack out, then, a good percentage of those writers will lose dominance, and a different breed will move in to the top spot.
I don't think it has anything to do with a writers ability, but more on what fanbase and profit margin he/she appeals to. Johns is a perfect example. He has targeted the mass audience of fanboys, and has absolutely bowed to their every whim (see GL: Rebirth). Thus, he has established a mass following, and substantial profit margin for the company. Do I like it? No. It's repetitive drivel. Does it sell? Obviously.
Are most comic authors simply fanfic writers? Not neccessarily. They simply appeal to that demographic to make a sell, and thus, fall into that category. So, don't blame the writers, simply because of the mindless herd that follows them. Blame the herd for not having the same taste as you.
Just my opinion...
