I agree with the statements above that kids don't play outside as much anymore. As a kid I remember heading outside at 9 am and not coming home until dark.
Our local rec league has strong participation, so much so that there aren't enough fields to have practices once the season starts. So kids are scheduled for 7 or 8 practices before the season and 2 or 3 of those are usually rained out.
So now kids are thrown into the game without getting any quality practice time (and they don't play catch or wiffle ball or stickball at home). At least half of the coaches have an "it's my destiny to win the rec league championship" mentality so the kids with lesser skills get minimal playing time. These kids feel embarrassed out there an the field and in actual fear of a ball coming near them.
I coached rec ball again last fall with 11-13 year olds and as it happens every year I was once again surprised that half the kids still had no idea how to throw a baseball. So I'm supposed to teach these kids "big boy baseball" with leadoffs, pick offs, balks, and infield fly rules and half the team still doesn't understand when a runner is forced out and when he needs to be tagged.
It's no wonder that kids give up the game before high school. Why would they want to play when no one teaches them how to play the game and they are throttled by lack of facilities? It's like saying, "Here, you're out of college now go be an astronaut."
My solution is that there needs to be an emphasis on coaching as well as a suburban push by MLB. Major League Baseball does a pretty good job bringing the Play Ball program to urban areas, but they need to hit the suburbs as well. MLB also needs a youth coaching initiative and local rec leagues need more league wide baseball skills clinics ALL SEASON LONG to supplement team practices. Lastly, more MLB players need to step up like George Springer to provide more baseball fields throughout the country.