OK, I am a grammar snob. But I also (like to pretend that I) have a slight critical distance from my stance. I think that some of these rules are just like a secret handshake, designed to sort the ins from the outs… Just sayin. Sorry “sayin’.”
To complete the typical mixture of ad hoc rule, intricacy in practice, and anxiety over error, comes the appalled response when people get ‘its’ and ‘it’s’ wrong or ‘wrong’. Alleged correctness is a key code by which you tell those with a really punctilious education and those without: the apostrophe is a marker of power, not of any linguistic meaning.
It is pleasing to know that in classical rhetoric. Apostrophe is the term used for highly elaborate and artificial lamentation. It’s not changed its meaning significantly. The wandering apostrophe has become the most recent stimulus for the lamentations of the poor souls who place all their faith for order, sanity, the civil and decent processes of life, on the strict memorisation of the set of chance-constructed ill-reasoned conventions of writing – those who cling for survival to a floating comma.
The Selling of the Australian Mind by Stephen Knight