For me, it is not a matter of formality
In fact, the US can be very informal while keeping it politically correct - gender neutral, for example
It is respect - how to be addressed in a manner that has no indication of my gender
Another person cannot assume that how they treat others is correct - generally speaking
If the other person raises valid concerns and doesnt like it, he/she deserves to be heard and action corrected, not just assume certain conditions override others - again, generally speaking
When I visit other places, I take into account regional differences unless it is an obvious offense (violence, physical, verbal or sexual, for example)