I think you're looking at this in the wrong way. The whales make hardly anything from posting, it's all in the curation rewards.
They will especially upvote anything that has the potential to bring in new users to Steemit as this is the strategy that benefits the size of the market cap the most.
Boycotting the whales will do nothing.
They are in actual fact redistributing the wealth hugely and building up a base of dolphins that will continue to do this.
I have a few articles on the subject if you're interested.
RE: Minnows vs. Whales = 53 votes worth only .20 cents