If I would do that, than the 2 sides always need to be connected. One of the things I want is to be able to do, is to have only 1 side connected in some scenarios. For example: sometimes I connect my computer to the TV for gaming, in which case, I'd only need to take 1 half of the keyboard and a mouse with me (which saves space on that table).
Great idea, however, it doesn't fit my needs. If it would have been the case, 2 controllers wouldn't have even been necesary, but alas.