I am sympathetic to your arguments, as @carlgnash just managed to convince me they weren't as incontrovertible as I'd thought on this post.

Whales can just buy votes from bots. Such a rule would do nothing. It's also how to get around the 4 post limit. Just post from another account.

I'll reiterate here the reason that it's a good idea to split rewards 50/50, since you may not see my earlier discussion with @carlgnash.

It's a trap to focus on the labor of writing or creating content as a guage of it's value. This is illustrated by the old saw about 100 monkeys typing out Shakespeare eventually.

The value in content comes from the ideas presented therein, and curation is the act of delivering value to those ideas via the market. While the act of upvoting is trivial, seeking out good content (particularly on Steemit with it's broken feeds) is a significant task.

Also, ALL the curators split the curation reward, and thus are but fractionally rewarded compared to the author. So the dichotomy isn't quite as stark, except for posts where whale curation might dominate the curation reward.

While it takes significant labor to create good content, it takes labor to produce crap content, and one being rewarded and the other not depends on good curation.

It's worth compensating.