Do you as an adult find it impossible to be friends with minors?

I notice a lot of people refuse to talk to minors online or exclude them from gaming groups, and I am just curious why.

Is it because they annoy you, or are you worried other people might think it is weird?

I personally have never had an issue playing games with people under 18 unless they are acting like jerks. I am a parent myself and really enjoy playing games with my kids as well; I often play DBD with my daughter and her boyfriend. I am capable of laughing, goofing off, and having just as much fun gaming with younger players if not more than I do with adults. Maybe it is just because I am childish and goofy myself. The thought just crossed my mind and I was wondering (no judgment, just pure curiosity).