An important function of language (and accent) is to distinguish between groups/classes of people. Makes it easy to tell if someone spent many years at school,

An important function of language (and accent) is to distinguish between groups/classes of people. Makes it easy to tell if someone spent many years at school, or learnt a "trade", to tell people from one (monied) area from a less affluent part of town. For this function, "correct" or "incorrect" use of apostrophes (like an accent) is serving a very clear purpose - telling others your position in society.