I can’t think of a not insane reason anyone would need one.

At work, I have a freezer with a couple thousand dollars of product in it. If I lost power and only had male plugs to jerryrig the generator into the circuit, I would. BUT only after turning the mains off and padlocking the panel shut. I didn’t have to do that as I just wired the generator directly to the freezer after disconnecting it from the mains, but

Wait, an electrical outlet can be an inlet too?