I think you're confusing fun with youth and ignorance. As you grow priorities change. I never said everyone should wear a fullface. I've been snowboarding for 15+ years, when I started no wore any helmet.
I think you are confusing youth for stupidity.
I can't claim to have snowboarded for anywhere near as long as you, hell that's not far away from how long I've lived.
When I started I used a helmet. As I got better, I stopped. Then when I started freestyle, I used a helmet. As I got better, again, I stopped. Sometimes I fall and it hurts, but for me, nothing will beat the authentic rush, and freedom, that comes from not being restricted. I'd never judge anyone for a second for using a helmet, I just personally feel that a full face is a little excessive. If someone wants to do it, go for it. What other people think doesn't matter. I just see it as having more negatives than positives.