Somehow the geometry of this escapes me. Couldn't you just unbolt the rims from one side and install them on the other? This would reverse the direction of rotation and make any tread patterns contact the ground in the right direction.

Are there actually Left-hand and Right-hand tires? Leonard's description of the advantages is pretty convincing. The regular way is to to sell four identical tires that can be mounted in any position. In this case "mount this side in" is incompatible with asymetric tread. Did the tire supplier sell you two left and two right - or was the mistake made there?

A third possibility is that there really is only one tire and the manufacturer botched it when they labeled them "this side in".

My favorite theory is that the tire supplier knowingly gave you four left-hand tires for the reasons mentioned by Leonard: they were upset that you took the steak to another restaraunt to have it cooked.

I always like to have a fully functional spare mounted on a matching rim. With these side and direction specific types would I need two spare tires?

Flint