The only person that has the corect answer is the inspector or you could try and ask for the amendments/electrical code. Many places here have their building code online.
We don't use Romex here but the first thing I thought of was what if you only had a 1 BR home. Or a 2 BR you wanted to put on 1 circuit. What if the 2 BR home had the BR's on different floors or sids of the house.
My guess is just another code mith. Probibly came about by an apprentace saying why do we need to use this stuff and an owner not wanting to explain just saying bucause it's code now.
