I ascribe to the notion that wheel size aught to be optimized for the frame size so you can keep frame geometry the same. 700c wheels on a 46cm road bike is dumb, and you can see how the frame has to be butchered to accommodate it with stubby head tubes that won't let the minimal insuring mark on a string stem get covered, and then look at a 67cm bikes seat stays and how a larger wheel could take advantage of all that space.
Japanese bikes in the 80's saw the scaling of top tube length match the frame size, when will we see wheel sizes scaled to match bike frames? We already have so many sizes in use how hard would it be to mate frame and wheel size?