Younger people have a lot of interest in technology and investing or creating their own apps.
They learn quickly so it's no surprise these are well represented.
Older people take a long time before decisions to invest in something. They are more wise about money and it's value.
I partly agree with you, but still the first geeks who were into technology and the first to believe in blockchain and use it to this day are not young guys, but people of a certain age. They are probably 40-50 years old now, so I would not say that only young people use this technology, although most of them do now. But I think that, as you said, they are not only using bitcoin but also different coins.