Harold has a good point.
The NEC originally has a square footage requirement, before the balcony required a receptacle. That requirement was removed, essentially requiring all balconies to have a receptacle.
The problem is that many buildings have 'balconies' that are no wider than the patio door that faces them. While it's fine for the balcony light to be mounted above the door, or to the side of the balcony, neither location is very good for a receptacle.
Hanging it from the railing is not much of an improvement. You're still stuck with a junction box- which has to be accessible.
I don't care how 'good' floor receptacle have become, I really don't want one out in the weather in a place like a balcony deck. Plus, if you want to be out on the balcony jackhammering the deck, you're a braver soul than I!
Time for the AHJ to use his authority to waive the code requirement.
