Well, I haven't watched any of the recent episodes of Pokemon, (but I still play the games and watch the movies), but I would never call it "childish." Sure, the Pokemon franchise as a whole was geared towards children, but nowadays, even parents play Pokemon with their kids, and I'm pretty sure that some watch it with their children as well. And life's too short to worry about what other people think, anyways. Just keep on watching to your heart's content!