In Western societies that concern often derives from the 6th chapter of Paul’s letter to the Corinthians, and similar sources.
Well there was a time when the church played a larger role in our societies. That was not a bad thing. In a nation like ours however, you do not have to belong to any faith and should therefore not have to modify your behavior in order to not offend a religious person that you do not even know.
We have no right to not be offended in this nation, especially when we are sticking our noses into someone elses private life as long as they are harming no one else.