That story about the ACL is just unbearable. Although, of course, it could have happened in the first practice at the new school, too, or any time - or while riding a motorcycle, like Tatis. So you can't really blame summer ball for that. Of course, if they didn't play during the summer, they wouldn't get injured - but they wouldn't be playing. That's like saying a kid shouldn't play high school ball because he might get injured for the travel season (or vice versa).
But I totally take the point that baseball players have a lot more to worry about, these days, than just how they are playing and getting injured.