I take the opposite view to the OP. If I see a group of people ambushed by something Big and Nasty, I expect them to come out with language stronger that 'Oh blast, would you look at that.' Profanities are part and parcel of the world, and ought to be part and parcel of an alternative fantasy world based loosely on our own. New words and artificial curses jar as badly as any other attempt to change language by crowbarring new syntax into an established language.
If I play an adult game with violence, sex and highly dubious magic, I accept swearing as part of the 'grown-up game' package.
I hate how everywhere tries to ban beautiful profanities.
