I took the official late date for the sake of an "early grave" argument. It's sounds even stranger if counting from Sandman.Vertigo unofficially started with Hellblazer and Sandman in the late 80s, but wasn't officially it's own label until around the time Preacher started in the early 90s. It was the last wave that you mentioned which killed the line. The honcho running the label decided to let Quinn and other NPCs infect it with cancer like Goddess Mode and Border Town. If they had gotten good writers like Morrison, Millar, and Ennis instead, it would still be alive today.
Why stop there? "If only they had Alan Moor and Stan Lee there!". Has it never crossed your mind that none of those people cared at that point? That the reason Zoe was there was because she was the only one willing to go there? The checks aren't fat enough to neglect a job on which you can write whatever so why weren't they there?
This is exactly the same commentary Lewis provides. "Something-something editors = bad. Was it his fault? Meh who cares".