I just tell them to just go away. I'm like in Year 7 in School and that still people bother me about it despite me even liking the games, the manga, and even drawing Fanart of it on deviantART. I mean like, if they don't like it, then why even view it?
I remember one saying "lol Pokemon" when I drew a new character with an Oshawott on my dA account. That totally angered me so I just flagged it as spam. But it's pretty nice to see some of my peers in real life accept me for liking it and they still do like it as well, so I just hang out with them.