Pumps for water need electricity too.
Guests stumbling around in a darkened building is a VERY bad idea.
FOX interviewed people earlier who have a hotel room but are outside. The room is on the 3rd floor and with no lights in the stairwell, no electricity in the room, it sounded like they preferred to just stay outside.
I have to say, I might choose the camaraderie of fellow sufferers over being in a hot, dark, closed up room.