When I was in high school from 2007-2011, I took basic electronics class learned how to solder, learned Ohm's Law, had Recreational Engines class, took woodshop, had a home repair class, had two welding classes, did automotive repair, machine shop. Had a lot of fun in those classes.
I never had a go kart growing up. Dad was fine, but my mom always said no. My dad and I were supposed to build one when I was like 10, but I didn't know about Forums back then. Only thing I had was the How to build a Go Kart book from Northern Hydraullics (carbon dating myself with that one, they renamed to Northern Tool and Equipment) and we just never really set the time aside to build a kart.
I think in some ways, YouTube is kind of making them way more popular. We're long past the golden age of go karts, but it is having a Renaissance.