This makes little sense, except it one (possible I suppose) important scenario. If the regular iPads screen manufacturing is a bottleneck, more than other components, then that limits the number of people Apple can reach. If a totally different screen can be made in vast quantities by different factories/lines without too much harm to the full-size screen quantities, then fragmenting the iPad line in this way could hugely increase sales by removing the bottleneck. That could, possibly, be worth the downsides.