... Dwemer ruins are cities, they're not individual buildings. Most of their traffic is from within, not without. ...
In most of these ruins I get the impression of back alleys, service ways, and old storage rooms, not "cities". It's difficult for me to imagine a civilization moving through these ruins as there is very little to indicate anything ever lived there other than the robots. Where are the homes, the markets, the production facilities, the temples, the recreation areas? I've not explored all of the ruins yet, however, so perhaps I've just not seen them yet. One wonders why only the service corridors are preserved so consistently though, with just the very rare "special" room (usually a storage closet) tacked on.