Because Slumdog was over-hyped in the end - even if it took a bit of time for it to happen. And when I say over-hyped, I mean in that sort of way where anyone who wasn't paritcularly interested in the film was treated like a freak and the media were foaming at the mouth and wetting their pants in ecstasy every time they got the chance to so much as name drop the movie.
Clearly though, you're completely obsessed with playing the race card when it comes to anyone who doesn't appreciate the way this movie has been slobbered over. I've never seen one single other person bring up the race argument in any way in connection to less-than-delighted reactions to Slumdog before. It's just bizarre. I'm sorry - don't mean to get personal, but I cannot understand how you managed to think this argument up!