Anecdotal, but it does appear that the fluent use of profanity is expected in some social/cultural circles. The military would be a prime example. I think as these circles are influenced by younger generations they eventually succumb to the softening of the F-word. From personal experience, there can be a lack of distrust for someone who refrains from swearing. A lack of some use of profanity can come off as someone being sheltered, having a lack of street cred or general social awareness, etc.