On a recent trip to Greece, I found this being asked by businesses, especially restaurants and bars, but down to my hotel that I reserved with a CC: "Could you please pay in cash instead?"
It's not unheard of in Europe to get 2-3% discounts if paying by cash (particularly in computer stores). The reason is that in some countries, merchants pay that percentage of Visa/MC commission (and in case of Amex even more) plus a fixed fee per transaction. For that same reason bars usually accept cards only over a threshold of 5-10€ or so. Though if that happens in hotels indeed it is strange then.
Within the last year in Greece, the banks and ATMs all shut down for a few days. I can see why people would be keen to have cash (and specificaly, euros).
Thats kind of a different situation, isn't it? The Greeks are probably abandoning banks altogether and going to an under-the-table cash economy, given what happened this past summer.