Maybe the same reason I haven't seen Red, or Moon, or Pandorum.
Okay, so, shame on you. For Pandorum, especially. Because that's all the people who made Event Horizon doing the same movie but without studio fuckery.
I've only managed the first half hour of Scott Pilgrim, but I love it. It's a comic book movie that sort of takes the whole "we're all tired of comic book movies" into account. I guess the comics are sort of hipster-esque. I saw them on Cass's harddrive last weekend, so maybe he can chime in. But the movie comes across as a weird sort of self-mockery, and all the characters are lovable.
I'll finish it when I get home, so we'll see...