My insistence on paying cash for in-person purchases means that I can't—and won't—shop at a store that only offers self-checkouts. I haven't come across any yet in this neck of the woods that don't have at least one cashier, but if I did, chances are good that I'd put the goods down and walk out without buying.
I do understand, however, that most people aren't willing to make that level of sacrifice just to keep the credit card companies from tracking part of their purchase history.