I agree with this point as I stated in my comment above. Only for more valuable and right discussion, I would like to address a missing point.

• Even if the majority of whales decide to stake instead of doing curation, reduce in rewards unlikely occur.

The whole reward amount is constant regardless of consumed voting power. Instead of absolute value in voting power, relative voting power would be used to determine the rewards of individual postings. I guess each voter would have more power and impact on postings if people prefer staking than curation.