It struck me that nice as it would be to be able to rotate items, it would require re-drawing a lot of these things. However, if the items where merely flipped, then the old art could be re-used painlessly!
Consider the herbalist's bench; if you build it currently, someone working on it would be facing up and left. If you mirrored the art, it would appear to have been rotated 90 degrees so that a worker would face up and right.
The gain from this is mostly visual; it would look nice and allow us to decorate our cabins nicely and break up great masses of perfectly aligned benches.
Hopefully this would eventually include cabins themselves. As it is towns look rather monotonous, and even just putting the door on a different face would be nice.