I understand your frustration, I really do. It's hard to be yourself in a world where being different can be isolating. Being true to yourself and withstanding the pressure of "fitting in" isn't something you should hold against those who chose not to.
You should be proud that you have the guts to remain faithful to what you believe in but you need to understand that what you have and want in life isn't what everyone else wants. It doesn't make them weak, it makes them different and in order to gain the respect of your peers - you should allow them to be different from you without judgment.
I am my own person and have always been. As odd as this may sound, I too had the problem of giving too much of myself to friends and receiving little in return. That puzzled and hurt me. How my friends accepted my generosity, but when it was time for them to give - they didn't. Despite that, I never changed. I like myself - my loyalty, my compassion and generosity. I let go of the bitterness a long time ago when I realized the only one that it was hurting was myself.
Don't hold other people's flaws against them. We can't help but be who we are. The kids you are upset with are dealing with life the way they know how. Yes, it could be dangerous, but isn't that their decision to make? You would feel less angst if you only worried about yourself.
You don't have to be around people that make you unhappy - that's your choice to make. The only thing you can change is yourself - why not try to change your outlook on life or your attitude towards people you don't agree with? You are the only one with the power to make yourself happy.
Live and let live.