Why is it ok for people to swear in bars and nightclubs?

I am very sick of having to go to the bar and hear foul language from people. I swear but not all the time. About how many times I hear girls and guys swear every second when I am at the bar or in a nightclub, it disgusts me and I feel like slapping their mouth so hard and washing it down with soap so why cant the bar or nightclub owner make a rule saying that no swearing or profanity is allowed? They should throw people out of the bar for swearing so much!! ITS VERY OFFENSIVE!!! IF IT WERE UP TO ME, I WOULD MAKE PEOPLE WATCH THEIR MOUTH AND ITS EVEN WORSE THEY SWEAR ALL THE TIME IN PUBLIC AT A COFFEESHOP OR AROUND KIDS!