The obviously silly analogue would be that a merchant who dislikes guns could choose to hang a sign in their texas cafe with "no guns allowed", but they probably won't. That doesn't mean they WANT people to bring in guns, but that they think it would do too much harm within the market they're in to reject them. It would be a case of "reluctant acceptance of reality".

I think credit cards are the same. It should be self-evident that a merchant would want customers to pay with debit cards since the lack of interchange fees means the merchant makes strictly more money. Of course they want to make more money. But they also must accept that charging more fees for credit card users or rejecting them entirely would reduce overall customer base and profit, and so they accept that people can use credit cards. They want customers, not credit card usage.