Don't let them get to you. Face it, most kids are idiots, and too afraid to do anything that'd make them seem different or "dorky." I'd guess that most are just jealous that you have the balls to go do something out of the norm. I know that anyone who puts me down for doing something I love (and something that not only doesn't hurt anyone, but helps many) isn't someone I want to associate with anyway. So I don't let it get to me, and you shouldn't either
Also, all my geeky pursuits over the years have done me nothing but good. While most people my age I know are milling around doing college courses because they don't know what else to do, I'm about to start a course at Uni that should put me on track for my dream job in the games industry. Awesome