It is neither language barrier nor confusion, but rather intention, as shown by the user’s post on another thread. That post seems to indicate the user is fully aware and specifically made NSFW content to gain points.
The post also try to justify it by using a similar logic that drug dealers use - that they are simply the suppliers for a market demand.
So don’t automatically believe when someone says they are confused, or they meant to flag their models as NSFW but somehow the tagging didn’t work. More likely than not, they specifically made these NSFW or even por nography models to gain points and they don’t want to tag them as such so as to get a wider audience.