I agree and its certainly what I see these days. On the plus side fitness levels are generally higher across the board, as are eating habits and behaviours from what I can tell. If you want a goody-two-shoes culture then welcome to the promised land.
There is a flipside to that. I remember in my late teens and Twenties you would regularly meet up with your work mates and swap funny stories from the weekend. Shitting beds, boning a ropey old cock-collector or some naieve young bint, having a scrap or so, being locked out and waking up the neighbours by lobbing chippings at the window to wake up your Mrs / parents to let you in, giving each other abusive banter in the pub and learning to take and give it with new nicknames often found as a result. There may not have been textbook behaviour, or health conscious decisions going on I admit, but there was a wider range of fun to be had and there were stories and tales to enjoy as a result.
It said it all for me when at 42 years of age I had an absolute rare bender with a few mates. Got trolleyed in the pub, stumbled home but not before kipping under a tree and waking up at 3am to finish by homebound sojourn, while a mate picked up a ropey old mare and gave her a good goosing and sent us all a few pics. The next day I laughed as the pictures and messages went back and forth and people spread stories around the local sports club. But when faced with two youngsters (about 21-23 at a guess) who were old enough to enjoy the story asked what were people laughing at they gave a look of horror as the stories were shown. Unprotected sex was seen as a "serious risk" and my first heavy night in about eight months was deemed to be a "one way ticket to liver disease". I just think all this risk-averse behaviour taught in school has created a very precious generation in general. They aren't all like that, but they do appear far more easily shocked than my generation was.
I think Arfur Europe mentioned it is a rebellious reaction to their previous generation who were heavy drinkers. I am a big believer in action / reaction and overcompensation cycles in life. To the new generation they are being "new" but it is as old as the hills. My great grandmother had very Victorian values which were inspired by Temperance movement. Her parents had also been big drinkers and so my great gran's generation went the opposite way as over-compensation. Rather than moderating they all frowned on drinking and many were tee-total or sought outright bans on it. Here we go again I guess!
https://en.wikipedia.org/wiki/Temperance_movement