1. You haven't paid them for anything yet.
2. Wrong question!!! It's an opportunity. If I showed up for lunch and despite power being out (probably on the entire block or neighborhood) the proprietors were set up outside making cold sandwiches next to a sign that said "Sorry, power's out so only egg salad" I'd be thrilled. Here are people single-mindedly devoted to my experience.
That's really my point. It's an attitude problem. I want to spend my money with people who hustle when it hurts, and I want to do that for my users. I'm not saying it's not "fair" to close shop and blame the other guy. Sure it's fair, but the person who cares more is gonna eat (or make, in this analogy) your lunch... and the world will be a better place for it.
The relevant part of the analogy is that you, the end user, wouldn't actually know why the restaurant is closed. Could be a power outage, or it could be due to health code violations. Having this information accurately communicated to the customer could impact their willingness to return to the establishment.