I actually have a couple of thoughts on this, and some of these may not sit well with some...
-As the basketball coach at our HS says during this preseason parent meeting, "each kid has a place and is a major part of this team. It doesn't really matter if they start or sit each kid is contributing in some way. We are a school of almost 4,000 kids and only about 60 kids across all grades are able to play basketball here. Just making the team is a great achievement" --Your school may have less kids and not cut kids but that fact that he is playing a HS sport is an achievement in itself.
-There is great pride in representing your school. While its cool to say I play on this travel team or that travel team please don't underestimate the pride kids take in playing sports for their high schools.
-There are great lessons to be learned from this situation. In my mind, he went out for the team. The team is set. That means that you have already committed yourself to the team. Therefore you do not leave the team until the season is over. The team is counting on every member to be there for them. There is also a lesson is adversity here as well. If they are no good (and we don't know that yet) then your son will learn how to deal with a less then ideal situation. All of these are life's lessons taught to us by sports.
-Finally, I have an issue with the my son is better then this team undertone. While there are chances for individual glory baseball is still a team sport. Imagine if your son ends up getting some college interest. The college coach calls the HS baseball coach. What is the coach going to tell him. I remember that kid, he bailed on the team because we didn't put him on the varsity team his freshman year and he thought he was better then the freshman team so he left us.