I'm an ex pilot, for a number of reasons, but the main one was that I simply lost interest. I thought that learning to fly was very interesting, but once I was licensed I rather quickly ran out of things to do with it. I had nowhere to go, and just got bored with flying locally,and my attentions drifted off to other things, but maybe that's just me. I suspect not, since so many pilots stop flying after getting their license.
At this point, since I have a family to support, there's no money in the budget for it anyway. Could we rearrange things so that I could? Hmm let me ask all all the affected parties: Honey, you don't mind giving up your kitchen remodel so we can buy a half share in a 35 year old airplane, do you? And girls, you don't really mind giving up your dance company so Dad can fly that airplane 80 or so hours a year, do you? After all, we can probably take it to the beach once a year, provided that the weather's OK. Yes, I know it's cramped and noisy and we can't take much luggage, plus it scares the crap out of your mom, but it will be fun, right? OK, we'll take a vote, so what do you say? Anyone care to guess the outcome of that vote?
I've been involved in a number of activities, and in all of them, many of the participants all think the reason "their" activity isn't more popular is because it isn't promoted properly. So far, it's never been the case. Private aviation has a number of challenges. First off, it's crazy expensive. I'm at a very senior level in IT, our household income is around the 80th percentile and we live in a moderate cost of living area, and it would take some major rearranging and cutting back for me to fly even 50 rental hours a year, and it's not fair to everyone else to do that. Second issue is that most people aren't all that much for the sensation of flying in a light airplane, they find it dull. One of my hang gliding friends described it as being like driving down a straight road in your car at 35 mph.
Let me keep going. The next problem is that the average GA plane has limited transportation utility. If the trip's less than 200 miles, better to drive, and more than 500, better to fly commercially. Depending on where you live, an instrument rating may be needed to get decent dispatch reliability. Also consider how many families have two earners. If the lady of the house is working half the hours, you can be certain she's going to want to have half the input on where the money's spent, and considering that far fewer women are interested in aviation than are men, there's another point of contention.
As far as that contention that Americans are lazy, let me point you to two sites:
http://www.runningusa.org/state-of-sport-2013-part-III?returnTo=annual-reports
http://www.usatriathlon.org/about-multisport/demographics.aspx
Look at the levels of participation in these two sports. Both are booming. The trend now is towards human powered or natural powered activities. When I was a kid, a dirt bike was a motorcycle, now it's a bicycle. Every weekend when the weather's decent I see dozens of road cyclists, and every day the weather's not horrible, I see runners.
GA's not dying, but it is shrinking. Back when I was flying, I think there were a lot of guys taking up flying lessons, and either not finishing them or finishing them and quitting shortly thereafter, like I did. Now, I think they're just skipping the starting part, and why shouldn't they? Unless you really like the sensation of being aloft, you've got to have a damn stout family income to get any utility out of the thing. And quite honestly, if you are really in this for the sport of it, hang gliding, paragliding, or sailplaning are more affordable, and for most people, more fun.