But I think that is your own personal confusion since:
CVS's
M.B.A.'s
are both valid - the apostrophe is sometimes used to show plural.
I am not that interested in picking the nit but you tried to insult me in relation to using "'s" to show plural in acronyms - you clearly did not understand that "'s" is sometimes used to show plural. Your attack was bogus, uncalled for, and lacked an understanding of the subject.
I do find it funny that you feel published word definitions need not be followed but published punctuation guidelines must be rigidly followed without any variation or deviation
What I like best is that it appears you've just been misusing apostrophes all this time, then when caught searched for a style guide to support your use. I don't think you've been using them thoughtfully and on purpose (which allows you to make exceptions for clarity) due to the other apostrophe misuse in your writing.
But you're right, it's (not "its") a tangent. We can end it.