It's humourless, homogenous, prissy, inhuman (in the sense that it removes emotional context) and fucking boring. Correlating professionalism with the above is very USAian. You should focus on breadth of successful interaction on the human side and ongoing effective fulfilment of job description. Not sure where religion comes into it outside of the Puritans who buggered off to America.
I am quite sure that the concept of "polite conversation" is not american or puritan-centric.
In my experience, the people using the f-word in business interactions are the same people trying to con me. Maybe this is because several of my early experiences correlated this behavior with people trying to get me to join Ponzi schemes (these 'businesses' often target college-age people in the US).
The phrase "polite conversation" is meaningless in its ambiguity. I assume from the context that for you it refers to words one may or may not use to maintain propriety. To me it refers to the meaningless pleasantries one uses when temporarily sharing an environment with strangers.