Reading Big Jim's post made me recall some changes I have observed myself in recent years. Young people (under 50) don't seem to have the patience or desire to spend as much time on activities as we did. In our area, country clubs are dying on the vine due to the lack of desire of many people to spend all day playing golf. 20 years ago, I and my close friends looked forward to our monthly archery club shoots, which fizzled out about 5 years ago. Since then, somebody or another would comment at monthly club meetings that we should start it up again, but nobody wanted to take the reins, so I finally volunteered. After 8 months, I can never seem to get more than a dozen players, so I plan to fold it up again at the end of the year, because a dozen people is really not much of a competition out of a club with 350 members.
What the new members do like is the ability to drop in casually and shoot a round in an hour or so on their own terms and their own timetable, with or without friends. The ability to offer this spontaneity may be a reason for our uptick in memberships in general, and possibly even the uptick in interest in trad archery vs compounds. Trad archery has always seemed more spontaneous to me than compounds, but that could just be the way I feel about it.
Hunting is an activity that requires dedicating a large chunk of time, more than a round of golf or a club shoot (although less often, generally) and the lack of desire or ability of young people to commit that much time to an activity could be a reason for the decline in hunting among that age group.