When you have a parent who played college sports (as is true of many here), you know how to train you sons, or how to find appropriate trainers and instructors. When you don't have that kind of parent, you do tend to hope that the summer travel team coaches will instruct the players during the summer. It took us a few years to realize that that wasn't necessarily the case. Had some coaches who didn't seem to want to help even when asked. It was frustrating.
In fact, this is something I always wondered about. You can go to an instructor and work in a cage on, say, batting. Can discuss the swing, the mechanics, etc. However, the other dimension of batting is what your approach at the plate is, how you are seeing and reacting to actual pitches in games. If the instructor doesn't see you in games, then who should be helping you with actual plate appearances? I always assumed it would be the coaches. Didn't always seem to be the case, though.