a few things to consider:
-2 regions worth of players vying for spots on 1 team to play 3 games. Not enough innings to go around
-someone would have to drive a long way to your hometown, too
-showcase designed to promote kids to college, sophomores have plenty of time to be seen
-a lot of kids are previously known about because they were good players for their high school. If a kid doesn't shine for his school's season, he probably isn't going to outshine many others in the showcase
-these tryouts are conducted much more professionally than many of the pro or college "combines" you will attend
and lastly, we all know that all answers are in the bleachers if only someone would take the time to ask those perched there.
These coaches do this solely for the kids. To promote them to the next level. There is no supplement, no bonus, no prize, not even a trophy. But it still gets done every year. And every year a number of kids who were previously unsigned, receive a scholarship offer they didn't have before.