From an interview in DeathRay Magazine (in which you can tell the interviewer is stunned by some stuff he comes out with and tries to meekly talk him round, to no avail):
Alan Moore on DC Comics: "A crowd of morally leprous people"
On Marvel: "An equal level of scumminess to DC"
On Frank Miller: "300 is homophobic, vaguely racist and above all incredibly dumb"
and "Did you see Dark Knight 2? It was really sloppy and cynical - it looked like he'd done it over 3 weekends"
And I found this funny - re a work he did for a gay charity: "The organisation were, by and large, a bunch of ungrateful bastards"
Great writer, but what a miserable old git...