I would also like to make my comments because I think it's a great question to pose. I am now a high school coach and had always been opposed to high school summer teams for the reason that many brought up. There are pro's and con's to running a summer program but the opinion I've come to is that the pro's do outweigh the con's.
I think our high school head coach summed it up best when he told our parents that summer is really our only time to teach the game. We have fall workouts right now where we can't teach, and really only about a month of practice time before the season begins. The summer is the ideal time for us to work with guys because of the lack of restrictions. For the success of our program, it's beneficial to have that time together. We have one successful travel program in town and we tell our players that if they make the 18U team, they are welcomed and encouraged to do that because we know that team is well coached.
Now, good coaches do need to enhance the experience. Someone mentioned the lack of competition. There is good competition out there, a coach just needs to find it. You might mention the lack of exposure. The coaches should seek out reputable showcase opportunities and encourage players to attend those. It's part of creating a well rounded program. There's nothing stopping high school teams from entering elite tournaments. So you can't really blame the concept of high school summer ball on lack of competition. You play who you want.
Someone also mentioned about Farragut not having a program. They've obviously an influx of talent like no other area in the state. I think it would be unfair to use that comparison. Just look at Bartlett and their success. They stay together. You could make the argument either way.
The point I'm trying to make is, if you have a coach committed to the program, teaching the game, and creating a challenging and enriching experience in the summer, then high school baseball is the best option. If the high school program just throws the team together, gets someone else to coach it, or just schedules games without using the time to teach, then I think those teams probably should just take the summer off.