The comment about the identity of the AC was, I thought, completely neutral and inoffensive. It actually is important to distinguish between the Gulf of Naples and the Amalfi Coast. They are quite different in accessibility and tourism lifestyle.
While I'm not against visiting Sorrento (I've been there twice, but I don't need to go again), it's fair to call Sorrento more of a mass-tourism location than, say, Amalfi. Even very popular Positano has its capacity limited by rentable rooms, and it tends towards higher budgets than Sorrento. Put crudely, the TA Sorrento newsboard is regularly asked, " 'ow much is a Pint?", while that question never comes up for TA Positano.
It often not clear enough that recommendations against car rental in these two areas (and, certainly, for visiting islands) is not simply moralistic whale-hugging. It's entirely practical in nature. I hope the OP has booked hotels as well as air, because all these destinations book up months in advance.