These businesses are already almost "cash only" businesses. Using BTC doesn't really help. The weak link here is that they need a place to do business. And if that place is getting shut down then all the money in the world isn't going to help.
True, this business is cash mostly and the main problems associated with it wouldn't be helped much by bitcoin for now, in today's landscape. (no pun intended). And btw, if I had a shop like this I would make sure I had my finances in the most transparent way possible, thats for sure.