Because reading or hearing swearing makes a lot of people feel uncomfortable, even if they occasionally swear themselves?

I know that on the odd occasion I’ve come across an NPC that swears I’ve found it quite unpleasant. Allods is quite sweary, probably due to cultural differences between the Russian originators and the very good but not entirely idiomatic English translation. I like Allods, but I’d like it more without the swearing, even as mild as it is.

One of the very first things I do in any MMO is make sure the euphemistically-named “language filter” is On. Given that I really very strongly do not want to read other players swearing, there’s absolutely no way I would play any MMO that allowed swear words to be used by NPCs, even if it was intended to be naturalistic. Very little else in MMOs is even marginally naturalistic anyway and one of the prime reasons for playing is to go somewhere that isn’t like the world around me.