The "whole-house" thing may be more dangerous than none at all for another reason.
Take a scenario where at bedtime something in the house (someone mentioned old fridges? could be anything actually) causes a nuisance trip. There was no actual electrical danger to anybody, but it has now plunged the whole house into darkness.
In the course of making your way to the meter cupboard to reset the pesky thing, you trip over the cat on the stairs, fall to the bottom, and sustain a broken leg, or worse.
The dangers of having fixed lighting circuits protected in this way seem way out of proportion to the (very small) chance that someone will get a fatal shock off a ceiling fitting.
Perhaps more debatably, nor would I be very keen on the idea of a deep freezer full of food getting knocked offline by a nuisance trip while we went away for two weeks in the middle of summer. I wonder what the insurance broker would have to say about the claim for replacement. They will certainly pay the claim if the freezer itself develops a fault, but when we talk about the electricity being turned off for some other reason, there's too much wriggle room there for my ease of mind.
