I have a theory. It may be completely wrong, like many of my theories.
People that are 'different' have a tendency to recognize people that are 'different'. For example, the famous 'gaydar'. Part of that I think is that people that don't quite fit in are always looking around at others and thinking "Where do I fit in?"
Teenagers are going through massive changes themselves, and are looking to see where they fit in. So they are more likely to spot something that is out of the ordinary.
Unfortunately, many teens are very uncomfortable with themselves, or are lost. And instead of embracing difference and exploring, they often times lash out. They are afraid to be different, so they will attack things that are different. Some of them do embrace difference though, and that's a great thing!
So I say, don't worry about them. They are as afraid of being found out for being 'different' as you are (and some maybe even more so).
That's my theory anyways.