Yeah, and look how much his heart is in it when he does. Like the mass amount of recycled material(and outline-deep plot) in JLA: NEW MAPS OF HELL. (For Perry White's rant, for instance, see either the beginning of the N-Zone story in Ultimate FF--Dr. Storm--or any number of issues of TRANSMET)
There are two Warrens. There's the one who writes great, original creator-owned stuff and is a joy to read. Then there's the one who has a family and needs to pay the bills and writes ULTIMATE EXTINCTION(gyuh) as a favor to Mark Millar, and tosses off shtick(and tries out ideas he'll use better later). At this point in his career they had not yet become as clearly divided and easy to distinguish.