Im not sure what is it about me?

It's not you. It's them. They're the ones who feel the need to point out what they believe your flaws and faults to be when they could be doing something better with their time. It gives a person pleasure sometimes and makes them forget their own flaws by criticizing others. Especially, when they're teens and in groups. Keep your head up and do your thing, whatever it is that gives you even the slightest bit of joy.