It is my observation,that an accent is considered the equivalent of a handicap.For the same reason that an American does not inquire about a person's limp,that individual will not ask about the origin of an accent.
Is it a lack of interest,a measure of ignorance,or is it out of fear for stepping on unsollicited turf? After having spent many years in different countries,I still am pleasantly surprised,when somebody candidly acknowledges my accent.I wonder if my observation is a shared one?