Anyone below an international corporation isn't getting cut in on the benefits. Maybe the big hotels and car rental (being large enough for the card companies to negotiate such a thing with in addition to having a significant enough percentage of foreign card transactions) services would see some benefit from that but I don't think most places would care.

There is always the other side that, although it's not a competitive exchange rate, at least you know the exact amount in your home currency. Also, I never remember which cards have foreign currency fees so it is a bit of a wash.