Here's an article about the numbers decline of pilots. I think the article hits on the two main reasons kids don't learn to fly... it's damn expensive and it's hard, with lots of math and navigation. The latter I see in my job all the time... we have to teach kids how to read maps and compute lots of things, and the usually hate it... it even extends to driving standard transmissions... doesn't seem like a lot of kids know how to do that anymore. My wife's a pilot and she's adamant that we'll find the money if our daughters want to learn. We'll see...
well, it's not a very cheap hobby. My dad got his during a summer a few years back. Everytime he comes back from Saudi he flies around here at some airport off of 290, north west of town. I've gone up a few times with him and have seen the $$$$$ it costs....damn.