Just because you have never been directly affected by it doesn't mean it isn't real.
I was a plenty outdoor kid, rode bikes, mowed the lawn, swam, all that nonsense. Still a space cadet.
The prescription movement's a little alarming because it's just another quick-fix solution. I can speak personally that it made me a different person. Not better or worse, just a little different, and that's...confusing as a kid. On top of that, studies have shown that it really works best when combined with therapy, and yet too many parents don't also seek therapy.
Now why is it on the incrcease? Partly it's increased awareness but I suspect there's also a strong environmental correlation.