I know what the editors said. But they were either lying (which is standard fair) or have very messed up ideas about being objective.
Actually, allow me to suggest a third way perspective here, which might actually reconcile your position and mine.
Millar believes himself to be a liberal - on this, I think that you and I can agree. The problem is, and this is where I'm coming from, he's not really. He may not like Bush or Cheney - and indeed, you provide rather overt proof that he doesn't - but when it comes to his politics, as they express themselves in his character dynamics (as opposed to his relatively simplistic declarations of OMG X IS WRONG in his stories), he really agrees much more with Bush and Cheney than he doesn't.
Again, with the exception of his runs on Superman Adventures and The Flash, neither intelligence nor compassion nor any sort of morality ever prove decisive in winning the day; rather, it's always the guy who's not just STRONGER, but MEANER, who's going to win.
This is why his Doom, and pretty much every other supervillain written by Millar, is so one-dimensional, because he wants his "heroes" to be completely unrestrained fascist bullies, and the only way he can justify this is by making their enemies almost literally INHUMANLY evil. Millar villains have NO redeeming virtues, because that way, no matter how bad his "heroes" get, he can say, "Well, they're only that bad because they HAVE to be!"
Short of Frank Miller, Mark Millar is the most overtly might-makes-right proto-fascist superhero writer I've ever seen, except that, unlike Millar, Miller is actually SELF-AWARE about it.