Reality is that aside from a couple of points of interest such as AH and bank, everything else is largely deserted.
That's why I think Ashran hub is very nice, because it has all the stuff you need in one convenient place and there is a bit of fluff on the sides and that's really all that is needed for a hub area that will be deserted once Draenor expansion is done.
No doubt there should be large cities, but it really only "needs" to be relegated to faction capitals. Tossing a huge immersive city in the expansion is a major waste, unless that city remains relevant after the expansion, I'd rather have that effort invested into actual content and not a momentary fluff.