The 'burp' theory of offense:

In some countries in the world, it is considered proper etiquette to give out a loud appreciative burp after a meal, as a sign that you enjoyed the food and to complement the cook. If you do not burp it is taken as an insult to the cook, and the host or hostess.

In this country any time you burp it is considered offensive to those within hearing.

A burp is just the sound of releasing swallowed air, a perfectly natural thing to do.

What is the difference?

It is a lot more than cultural traditions, it is what you have been taught as to what is offensive.

When people in this country complain that they are offended by Christian symbols such as the Cross or the Ten Commandments, it is because they have been taught that it is offensive for them to view it.

However these same people who are teaching that the Cross is an offensive religious symbol, are also teaching that you should  have 'tolerance', 'inclusiveness', 'diversity' and 'acceptance' to people of other religions, even if that "religion" be Satanism or Witchcraft or whatever else is the weirdness of the day.