My kids both like pokemon. I don't blame them... its collectible, and collecting is fun.
What did we collect when I was a kid? Hockey cards? Baseball cards? Same idea but a hell of a lot less fun. Especially if you didn't really care about the sport...
I'm vaguely surprised that Pokemon hasn't been replaced by something newer, but I'm not surprised that its still around. Nintendo has done well with the marketing.
Not just collectible, playable. I'm in my 40s and through my son got into the video games recently and was surprised to find a really well developed and balanced gaming system that was both simple to understand yet nuanced enough to allow for extremely detailed and varied strategies. Online we found in-depth analysis on team and move strategies and a worldwide community of online players. This isn't just cute monsters, that's the marketing aspect, Pokemon is an excellent game. We are now doing the card game as well, recently joining a local league - and getting our asses kicked.