It’s because there have been cases where people have been doing real rape videos and posting it on motherless. Not the kind where it says it’s real but it’s scripted, I’m talking about someone actually doing it without the other person’s consent. It’s been an issue for a while. Usually they limit specific words for a brief period of time when such a video is discovered, probably to avoid liability. After the heat dies down they usually unban the words again.
So if you’ve ever watched a motherless video and thought “wow that actress is really good at acting” and it’s some unknown person, there’s a chance that the person wasn’t acting.