I was a fucking music major at a performing arts program that was basically a conservatory in a liberal arts university with strong dance, art, and theatre programs in addition to the music program (basically all of the aforementioned programs are recognized nationally/internationally with people going on to professional arts organizations on a somewhat regular basis). Thinking that art is reserved only for those with proper training and that discussing what is art is reserved only for those with some sort of formal education is what keeps people in the arts as being seen as snobbish and with their heads in the clouds.

Do you not think that every human is capable of self-expression and could see that self-expression as art in some way? Yeah, I agree that people that spend the years/decades of focus and rehearsal and work to develop their technical abilities towards artistic endeavors can make for stunning/breathtaking/life-changing experiences. But, I'm not going to completely blow off someone who has their own interpretation of what art means to them.

Besides, I do agree that a teacher shouldn't be the sole determinant for what is art. A fair number of times I would disagree with my teacher about musical ideas, but would feel uncomfortable speaking up about it because there was a lot of pressure to conform to his ideas since he had held a principal position in a major orchestra for decades. Yeah, he has legit experience, but music is still a pretty subjective area and just because one person thinks something is right, even with all of his/her experience, doesn't make it right in my mind. It might mean you should really consider what they have to say, but it doesn't mean that their will is the will of the universe or some shit like that.