Come to think of it, I think you're right. They were either A)jealous over the fact that I have the courage to do it or B)someone in the past was a jerk to them.
Earlier in the day, I was on the chair with an older guy on skis, and he told me that he's wanted to try snowboarding, but never had the courage to try it. Told him that I really just started and the only way to do it is to try it out, and take some lessons. Guess some people are, exactly like you said, looking for a reason to be elitists dicks, and others want to try, but are nervous about it.
After some more thinking about it, I'm wondering how they would have reacted had I been on skis instead of a board. I did learn an extremely good lesson from it though. Stay well away from where trails come in at the sides. I know when I'm coming in from a side trail, I'll come to almost a complete stop to check uphill before going out(was taught from the beginning that when coming from a side trail that the ones on the main trail have the right of way).
It'd be nice to think that one day all of the stereotypes and bad attitudes would be gone, but unfortunately there are people that want to feel "above" others no matter what.