After viewing all of these varying responses it would seem that for the most part we all ALMOST agree on the premise of what I originally posted. lol. Well, to a degree that is. Listen, I know good and well if there is a Senior LHP in high school throwing darts at 97mph that is as cocky as they come and even his attitude out on the field showcases it are college Scouts most likely going to overlook it? Of course. Most of these coaches know some "upper classmen" leadership, running, humbling, etc can calm even the wildest beast once they arrive on campus in the fall. So who then needs to heed the advise about how to properly act at all times just IN CASE there are some Scouts and/or college coaches there to watch them, a teammate or a player on the other team? YOUR SON. In that case just share with him some tidbits that could make a great impression instead of a bad one. Maybe if your son is a Junior and that coach comes back next year he has good and/or impressive memories of your attitude or actions the last time he was there. Who knows, right?
It's only sage advice and wisdom that I remember sharing with my son several years ago. He wasn't a 5-Tool player or sought after by major D1 schools so anything he could do to help himself just in case a college was there was worth it. And having a good attitude, hustling, and being a great teammate was just something he enjoyed doing naturally.
YGD