>>715341464 (OP)For this simple reason
>Someone comments on your art piece that they find the girl in it hot>Comment back saying thank you and that you will be drawing more, maybe show sketch of it in reply>"Umm, ackhually I'm a minor despite not saying it in my profile???? Help!!! @FBI" etc.Makes it just easier to tell idiot kids to fuck off and that you don't want to interact with them. That way some fucking moral crusaders don't come at you for drawing problematic stuff(like anime girl who is 18 but was 17 when she was wearing that bikini you fucking pdf file!!!!)
So just easier for everyone and kinda mandatory on Twitter if you have bigger following or do nsfw stuff. Or just happen to retweet naughty stuff sometimes.
Had an artist friend go through that kind of stuff when someone accused her of grooming someone in DMs(she shared sketch of her upcoming NSFW drawing) who didn't have their age in their profile and claimed they were 16 but ended up being 18 but she followed her first time when she was 16 and happened to get a like from her in past so she was grooming her. Thankfully the thing dropped and the retard was made fun of but people rather be safe than sorry. Btw my friend was 22 when that drama happened.