Let me interject a bit of my personal experience, I believe it to be relevant to the topic. Firstly for those who are unaware I have Cerebral Palsy which primarily affects me physically, and I walk with forearm crutches. When I first attended Junior High and "Band" was offered I looked for an instrument to play that I might have the best chance physically of playing. I decided to "try" and audition for Trumpet to be quickly told by the "instructor" that "You walk on crutches, you can't play a Trumpet"

Needless to say that pi$$ed me off, but my point that I think is relevant here is this;
If that "instructor" hadn't been a douchebag and asked or looked at my passion for music rather than making a snap judgement I'd probably be much more educated musically speaking. From my perspective "instructors" can be just as big an ignorant a$$wipe as most students.
I wholeheartedly agree with the assessment on the tepid, apathetic, "I'm great" syndrome this society puts out, but the guy who you choose not to give chance to because of something as silly as I was told, will bite you in the A$$.
Don't waste time on lazy bastriches, but never assume something without legitimate cause either.
God Bless, Ray