To be honest, I don't think sticking with Warner does this - as I noted earlier, I think he is at best a mediocre QB at this point. I think it's pretty well established that Dennis Green is not the sharpest tack in the box, and this just confirms it. IMO this only delays the inevitable by a few games at most.
Yeah, I don't think there's any reason to have Warner at QB either, but "conventional wisdom" says that bringing in a rookie at this point is waving the white flag. Warner was never the same after the thumb injury, and although he can still rack up the passing yards, he seems to have real problems finding the end zone and developed a nasty fumbling problem(as you noted). This may have just been an overzealous reporter trying to get the "scoop" but Green's comments about "maybe I'll never win here" were kind of odd.
Warner benched after another horrible game. Leinart to start next week against Herm and the Chiefs. Way to give the game today away, Denny (not saying they'd have beaten Atlanta with Leinart, but they sure weren't going to do it with Warner).