I think my mom gave up on me letting Pokemon go haha. She never seemed to mind. I think she really quickly realized I am probably always going to be a child at heart. I like a lot of cutesy and childish things and still like plushies, so yeah. She doesn't really care. I think she feels like everyone should have something they do for entertainment. My dad thinks it's cool I have something I've been into for so long and hold so near and dear to my heart. No one else in my family seems to mind either, and has contributed to it in some way, whether they know it or not haha.
As for friends and such, they don't care. And believe it or not, once you get in college, you'll find that a lot more people play Pokemon than you realize. Heck, there was a group of friends that went to a coffee shop every Thursday night just to hang out and play Pokemon together. I was invited but never went lol. :(
POINT IS. No one cares, and no one should! It's just a game. Or show. Or whatever you mainly do in the franchise. Unless it's harming you or someone else, it shouldn't be a problem.