I’ve tried to analyze for years why young people are not getting into the sport, and I have simplified it down to a few things.
When I was young scuba diving/skin diving was still a fairly young sport and was still in the public eye through TV shows and movies. We played outside a lot and built forts, we were more adventure seeking minded. There was a lot more physical involvement in everything we did since it was a manual/analog world. The boob tube was the big evil then (remember the phrase “kill your TV”?). I grew up without a TV so I was always outside.
These days the youth has grown up with numerous electronic devices, computers, video games, three D interactive games, virtual reality, and TV seems to be almost benign now compared to everything else that kills time. They spend a lot more time indoors and the mental activity stimulation has become much more abstract while they don't use their bodies nearly as much.
Diving is a physical sport. Combine the plight of todays youth with the fact that there is very little exposure anymore about diving on any media starting with TV and movies and you get what we have today.
Pretty simple.