I *did* say "if many people did this regularly", but I was not trying to imply that I would do so. I'd do it one time at said store --- the first time I find out about it. After that, I'd either go to another store or probably use cash/check. I am not poor, but I *am* cheap. If a store is going to conditionally hit me with a fee, then I will do what I can to avoid it while wasting the least amount of time.
My own opinion on this change is that it is in the store's benefit to encourage people to use cards. It seems that most cases of armed robbery are cash-related offenses. Minimizing the amount of cash in the store should thereby reduce the damage from such occurrences. I realize that much of the cash should be locked up in a safe at most times, so perhaps this particular thing is a non-issue.
I also know that people do not like seeing extra fees on their bills. I have seen quite a few instances in the news where a small fee shows up on some bill (phone bill, bank accounts, etc.) and many customers "revolt". I believe continuing to keep the fee "hidden" within the prices of all their products would be better for keeping their customers' anger at bay and also — as the summary suggests — moving towards a cashless society.
I like using credit cards for the cash back, but as soon as it no longer pays to use a card, I'll stop using it. I have no allegiance to the credit card companies, and this extra fee may even be good at reducing their power and influence — which I'd say isn't necessarily a bad thing.