Personally, I have found that swearing / profanity is not necessary. One can express oneself without it. GENERALLY I have found that the more educated person swears less than one who is not as educated.
Since we get used to what is "appropriate" in our native area it can offend someone who is not used to it. For example - I grew up not eating monkey brains for dinner. Serving it would probably make me ill. However if that is what you grew up around you would not be offended.
Hence the "New Yorkers" saying that they are not offended. The problem is that in this world that is "shrinking" in size because we can all be a "family" without being near each other one needs to be aware of things that might ofend others and determine - what is the necessity of swearing.
If that is the only way to play the game then this person did what they needed to do. Their gain or loss. You decided NOT to censor your language even though it might cause you to lose this player.
Personally - when i am around people that swear a lot I usually leave as well. If they pass gas regularly - same thing. Belch - same thing. I usually choose more "pleasant" places to frequent.
Bill