I would say many people are still unaware what's happening with DCC based on informal observations at hotel receptions and discarded ATM receipts. Taxes (and some fees) are required. There are some fees, such as resort fees, that are a merchant cash grab. DCC is in the same category.

For smaller transaction amounts, it is about the principle, but there has got to be a threshold where most people would complain. For instance, if you had a restaurant bill of $90, paid $100 cash, and only received $5 in change, I'm sure you would speak up.