How should I convince my parents to let me continue Violin?

I have played the violin for 8 years and even got into a professional orchestra for teens. Now, my parents want me to quite violin since its the end of middle school. I really want to continue; having explained to my parents already that the reason I want to continue violin is because I really enjoy it, now in an advanced level learning the pieces I’ve always wanted to learn, and importantly, because I will take Violin as a Minor Subject in University. They still said it was a BAD reason and will force me to quite by the end of 8th grade. My parents have been verbally threatening me to quit violin for the last 8 years I’ve played violin. What should I do/say?