First, I'm going to attack the premise. I haven't seen anything to make me think there are more arm injuries than in the past. There are certainly more surgeries and you certainly can now come onto the internet and LEARN about more injuries than you used to. Twenty years ago, we didn't take our kids to a surgeon if he injured his arm. Matter of fact, it's quite likely we didn't even take him to the doctor at all. Guys who suffered injuries simply either quit pitching or pitched in pain.
That's how it was when I was in high school. I remember a LOT of guys who "blew out their arm." They didn't become a statistic because TJ surgery wasn't an option.
You do hear about hs kids (or younger) throwing 120, 150, even 175 pitches in a game. However, it's news because it's rare these days. When I was younger, I guarantee you there were plenty of games in which I must have thrown over 150 pitches and I wasn't alone. We didn't count pitches, so who knows. I can also remember that the studs went day after day and many of them "blew out their arm" in high school or college. I believe we're doing a much better job. I think injury rates are probably far lower than twenty or thirty years ago. We should keep learning all we can and we should protect young arms, but all this talk of an "epidemic" sometimes makes me crazy.