The two big problems I have are this - first, that anyone under 18 is being put into a highly-sexualised environment, even if you do everything to say: "this talent is under eighteen. No lewding, please". But the bigger problem is that hiring and using minors, even if intended to be legitimate, tends to attract people and controversies I'd rather not see anywhere near vtubing. We've all seen the shit involving Nickelodeon and Hollywood and so forth. That shit can stay right the fuck away from vtubing, thanks. And saying "no minors" is the easiest way to avoid that stuff. People that want to vtube can wait until they're 18.