Isn't the chain traditionally on the right because older sprockets were screwed on? So pedaling will only ever tighten them. Put them on the left and there's the potential to loosen the thread in operation - the same reason that the left pedal threads are cut the other way.
Given that the Trek experiment didn't produce any noticeable improvements, there's no real need to retool everything.
Motorbikes have an equal amount of left-hand and right-hand drive trains, because they manufacture their own components whereas most bicycle manufacturers buy them in.
I don't think it has to do with which side you mount them from.