>>2820257Because one is shota and it can attract the wrong crowd into the board (outside of /b/). Think of it as furries, which are also not allowed outside /b/ and /trash/, once you give them a pass they just start taking over, gotta draw the line somewhere.
And well, the other is just a general fetish that most of the time is just adults going at it while calling "daddy" or some shit like that, really what do blood relationships matter in fiction at this point? It would be like banning rape fanart or some other fetish.
Shit gets banned not because of morality if you're wondering, but because of management, the site would just be a free for all if everything was allowed and over the years the mods leaner that.
At some point, you gotta make rules and gatekeep in order to maintain the order.
