Some Nikkor lenses have been designed with the zoom and focus rings in different positions.
There is no rhyme or reason to it. Perhaps one of the engineers pushed the change for just the reason you surmised, but at a point in the design process when the product manager wasn't paying attention to user experience issues. The default exposure metering scale in the viewfinder is also reversed, but at least that's easily changed in CSM F12.
I remember retraining myself going from the D200 to the D300. When the D700 was setup like the D300, I was very happy and thought Nikon had it together at last. The lack of AF-ON buttons on the D600 and D7100 consternates me and now this button swapping on the D800. It makes me wonder whether engineering and photographers ever get a chance to communicate.
It does make sense to put that plus above the minus, but it should have been so with the earlier models. Now, they should have stuck with it. I'll just adapt
Scott Chapin Powder Springs, GA, USA Nikonians Team Member
Are you aware of the fact that you can program the OK button to an instant medium-level zoom in playback? This will greatly reduce the need for the zoom up/down buttons, as you can check focus with one press of the OK button.