I think you might be misunderstanding the point of delegation of power. We don't need minnows and dolphins to unite and create a new whale with 40 megavotes. We need whales to distribute their power to amplify the thousands of votes which are now worthless.
with an exponential rewards curve, whales would be penalized (in terms of influence) for doing this. It may be what we need, but it is not nec. what well get.