There's a nice interview with Grant Morrison on GraphicNovelReporter (see here). The questions have a broad, almost naive quality which prompts him to talk about his work and the industry in a slightly more candid way then when he's got a promotions hat on or when he's talking to someone who's trying to get spoilers or gossip. So general "what's your favourite piece of your own work?" (the answer to which may surprise you) questions often eventually lead to interesting quotes like this:
"...I think people prefer him (Superman) to be grounded, for some reason that I disagree with. I think Superman should represent the ideal, Enlightenment Renaissance human being taken to the limit, but there's always an appeal because Superman has always been a kind of blue-collar character. He started out as a Socialist champion fighting for the rights of the common man, and I think that's part of his appeal, but it's a difficult appeal at a time when we worship celebrity and money, so someone like Batman is this fetishistic, wealthy man who has a butler and is a more popular hero than Clark Kent, who has a boss who yells at him and who goes home at night, even though he is Superman. He has to put up with these sort of ordinary situations at work. So I think he doesn't have the appeal to a current audience that someone like Batman does because he exemplifies this kind of Simon Cowell ideal of the self-made multibillionaire who can do whatever he likes."