in how to deal with a child who hates their sport/music/etc. I was that child. And there has to be a balance, some things I could quit, other things they made me stay out the season.
Volleyball - had to play one year. I wanted to play, didn't like it, and was allowed to not reupp the next year, but I was not allowed to just quit on my teammates.
Saved money for acting lessons, got stage fright, terrifyed -- quit after 2 lessons. My anxiety was off the charts and it was hurting my physical and mental well being.
Summer job I wanted to get but then didn't like (we started out as friends and ended as enemies). Had to find a new job before I quit, and still give them the 2 weeks notice.
You can't quit everything, that's not gonna work when he's an adult. But there are ways you can teach teens what they can do instead. It's not all or nothing and should be looked at by activity and the amount of stressers it's giving the kid.