Hiya!
I'm gonna go with: "Sad, but true".
If I told you about my childhood freedom, well, lets just say I wouldn't be surprised to hear about my parents being brought up on "willful endangerment of a child" charges or something!

There were always those friends who had over-protective parents, to be sure, but the vast majority of my friends growing up from age 10 to 18 were pretty free.
Also, I'm not so sure its kids "not having enough free time" or having to "work D&D into their schedule" so much as they have
always had their decisions made for them. Yes, kids get a LOT of their decisions made for them by their parents, it's called "raising a child", but I vehemently opposed two of my friends parents quite often. We'd get over their to 'pick them up' (ride with him on our BMX's) and be told "Sorry guys, I can't go". When asked the reason? "My parents just want me to stay home". No reason. Nothing. They just arbitrarily decided "Naaa...you can't go anywhere today because, uh, we said so". Even through they KNEW he was going to go play D&D and they KNEW we were riding over there (or walking).
Anyway, yeah, I think kids have been brought up by FAR to many "Helicopter Parents" (I think that's the term). They never developed the skills to, well, tbh, think for themselves and enjoy the rewards, or suffer the consequences, of their actions. So you get 20 year olds who have to check their facebook, twitter, or talk to "everyone they know" about weather or not they should go play D&D for 5 hours after work. Worse still, if two or three of their friends say "Oh, well we were thinking of going out for coffee or something later, after supper, maybe"...that 20 year old will actually be conflicted about deciding to play. Because, well, two of his/her friends MIGHT go do 'something' at 'sometime' after supper. This sort of "decision paralysis" due to the psychological need to 'check with everyone else first' could very well be why a lot of folks play AP's; it takes the decisions out of their hands...because if the DM is asking all the players "Oooh...this next room has a pair of displacer beasts in it and some acid pit traps. Should I let you guys go into that room?", kinda defeats the purpose.
If my daughter wasn't autistic, she'd be out probably doing what I was doing when I was 9. ... ... ... Er... ... Wait. I don't think I thought that through enough.... hmmm....
^_^
Paul L. Ming