This will not work. I'm approached (mostly by unsolicited chat PMs) nearly every day by authors who want to pay me for my votes.
In fact, to some extent, objective evidence of this can be seen clearly on the blockchain by looking at any whale's wallet. Unsolicited payments attempting to buy votes are received constantly. Often these are 0.001 but sometimes they are higher. If higher payments are more effective then we will see more higher payments. These are unsolicited payments, but even without any explicit agreement, those sending the payments can continue sending them to the whales who comply.
Voting power has a value and a market will form. At the high end the amounts at stake are high enough that transactional barriers to such a market become insignificant.
Removing curation rewards has more effect on the middle and lower end where it reduces engagement and any opportunity for voters to be compensated for their contribution (since transaction barriers impede a side-payment market) than at the high end where money and power will always find their equilibrium regardless of the blockchain rules.
I think you are really on to something here. If curation rewards are removed, it removes the incentive to vote on content that other people find valuable. Voting will become little more than a way of distributing funds to authors. It would open the floodgates for abuse and bribery.
If you're worried about whales not voting in a way that benefits the platform, why would you eliminate one of the primary mechanisms for ensuring that they do so?