Pokemon isn't frowned upon, as it's one of those things that most people who consider themselves gamers either played it at some point or still are in secret. It's just got to the point with pokemon where the younger gamers don't want to admit to playing it because it's no longer 'cool', and the older ones don't want to because of embarassment as it is considered a child's game, which is a shame because it really can be a tactical game if you play against other, human, players.
Edit: - And I freely admit to running and playing in Pokemon Tournaments at conventions

Wish I could get a hold of the manga though...