It seems to me that this is considered a wall or is it not since it is spindles rather than a closed in half wall?
The columns missing a receptacle wouldn’t get a second look from me.
The 2006 IRC Commentary says:
If that is part of a habitable room and not a hallway it would need receptacles the same as a framed wall.
They should install one of them new “wireless” receptacles. Just duct tape it to the side of one of them spindles.