Ill speak from a minnow point of view since i think even the voice of the small stake holders has some value.
I agree with your sentiments to some degree. What i think we need to take into account outside the 50%, 60%, 70% etc loss in potential profit for large stake holders is the external effect that stems from our actions on blockchain.
Yes... In the short term it might seem you are at a loss of potential profit but as in real life societal growth depends on more then individual maximization of profit in short term.

Acting in a way that Kevin is doing is adding to the value of the platform. Acting in the way those that self upvote, delegate massive amounts of SP to bots, is hurting the growth of steem.

Our collective approach has a direct implication on the $ value.
What Kevin is seeing is lower gains in comparison to those that act in the way that is a detriment to the platform. And yes i completely understand his frustration.

Throughout human history more often then not those that act to detriment of society profit the most. Dan realized this which is why he put in a constitution on EOS. Pure ungoverned model does not work. People are so flawed that they are willing to completely kill any opportunity for long term gains in order to maximize short term ones. And here the few have all the power.
What we are seeing now is what happens when you let people completely govern themselves without any set rules.

They destroy themselves.
This economic model could have worked if human beings werent human beings.