People like that think they can't do anything in public they don't excel at. Like it's taboo. It sounds like your passion was mistaken for pride. You can sing without being a pro, it's something humans have always done. I've always been the same, its just so fun to sing and I remember lyrics and sounds better than any other information. A musical ex of mine got irritated with my singing one day. "You need to plug one of your ears so you can harmonize better!" he snapped. As if perfection was my perception or intention! I was just having fun, which was alien to someone as insecure, yet elitist as himself.

Don't let others' projected insecurities limit your human expression!