Hmm... Doesn't that one have asymmetric (that is, rotated rather than mirror-flipped) rooms, too?
I could see many arguments for having symmetry in really big and important pieces of machinery, and the transporters could be among those - especially if two are always paired to a single pattern buffer thingamabob, as in the TNG Tech Manual, and the overall machinery in fact is quite massive. Asymmetry in such big things could be argued to be visible to the outside; to unbalance the ship in center-of-gravity terms; or even to make the concept of concentric curved corridors a bit futile when the circular layout is disrupted on one side by the asymmetry already.
But a bit of asymmetry also gives character to the design... And the sets never were built to be symmetric anyway.