True. I've never run a shop.

However I know few of the shop owners. All of them are saying the same thing: problem is money or sometimes technical issues (e.g. someone doesn't know how to use computer or a terminal for card payments; doesn't want to learn new things; is afraid of new technology).

Most of the places I see that don't take cards are newsagents - hardly difficult to see why someone in that line of business might be a bit reluctant to make a capital investment.