I agree, and be7671 doesn't define accessible. this kind of thing is much more common in the design of non domestic installations...
This is why I sometimes come at these debates from a different angle. In industrial design not much about placement is standard enough for regs to cover it. All houses have floorboards and walls where things can be hidden, so it's easy enough to define all such places as needing MF.
Beyond domestic, there is just too much variability though. In a factory process line something could be totally inaccessible without major effort for a variety of obscure reasons, so it really does all hinge on common sense. In the same way bathrooms and kitchens are zoned in respect of them being wet areas. In my world a space not at all zoned could represent similar risks and it's up to me to identify those risks and factor them in to whatever is being installed.
Different worlds I guess... But the risks are in the end, generally comparable.