Quitting something senior year, how much will colleges hate me for it?

I am currently a junior in high school. I have been in marching band since 7th grade, and I have been the color guard captain since last year. This year, we got an awful band director that’s making everyone miserable. Marching band is very time consuming already, plus it means a lot to me emotionally. If I don’t do it next year, how much will it hurt me?

I’m looking to go to a top university as an engineering major.

Not at all, assuming you’re replacing the time with something worthwhile.

Agree, if you find something else worthwhile to do it won’t hurt you. There is no need to continue with an activity that makes you miserable.