I'm going to tell my friend not to accompany us to a concert.
Does your friend hate the band you want to go see?
Yes. I don't want to go to a concert with a friend who's not into the band.
I can see how that would detract from the fun. You're friend should feel relieved not having to sit through a concert listening to music they don't like.
I'm not doing this for my friends own good. I don't want to have a bad experience.
That's perfectly fine to do! You can't force someone to do something they don't enjoy. I'm sure they would be very thankful for you sparing them from coming along.