I'm turning 51 in couple of weeks. My dad bought me a '77 50cc trial bike in 1980. Rode that for maybe 4-5 years before 125cc enduro and then cars. Last year bought me a vintage 50cc "moped" again. I write "moped" as I am in Europe and the laws are a bit different than in the US.
Locally, some high school kids (15+ year olds) ride 50cc scooters or enduro bikes. But most of them are on bicycles though. Traditional mopeds are long gone, haven't seen one in my town for years. Seems like the whole culture is gone, only 40 years ago in moped heyday they were the most common type of motorvehicle in the whole country.
I think the youth of today are not interested in vintage ('60s to 80s) mopeds because their parents didn't live during that time either. 15 year old kids of today have parents who were born in mid '80s or later. The best days of mopeds was already long gone when they were 10-15 year olds. Other things were cool at that time (mid '90s to 00s). So, their kids are already 2nd generation past mopeds.
But, I do turn heads when blasting through town on my '73 Puch 49cc motored thing! Both adults and youth stop and look at me going. :D(edited)