Yes, well, odds are, they used to like it too but simply either grew out of it or were pressured into quitting. I remember saying a dumb joke in the 6th grade about two Voltorbs and a Diglett or something and everyone laughed. The catch? This was in a guy's locker room, full of all sorts: your nerds, your jocks, etc.
Pokemon is undeniably a phenomenon of the generation, whether one wants to admit it or not. Unfortunately, the show and hype of "cute" Pokemon is probably what did it in for most folks. The influence of society, aka peer pressure, is enough to distract most people from a solid, engrossing game.
And in truth, Pokemon is a good game and one which has evolved over the years into an even better one. And if players don't like the bells and whistles of the newer games, they've probably still got an old RBY cartridge lying around gathering dust and just waiting to be popped into a game boy. It is developing into a globally competitive game, especially with the nearing online applications, and it's a shame that the field of competition has thinned out due to such unfortunate circumstances.
And yet, when that tough guy you know is in his fiftees and his grandkids are begging for those newfangled "Efenectromons," he'll tell them, "Back in my day, we had Pokemon. Good ol' Pokemon. Got. To. Catch. Them. All."