It seems to me curation rewards make it worse, because the Steeminions have an extra incentive to vote with the whales.
This a common misconception. "Steeminions" are actually disincentivised for voting with/ after the whales. A low SP holder gets nothing for voting on a post after a whale. The system works to reward people for voting before the whales on popular posts. It penalises the 'johnny-come-lately' voter. Once the one's jump in, it is irrational for a "Steeminion" to follow unless they truly think it is an exceptional post.
There is no need for a whale to initiate a mass conspiracy of kickbacks etc. They can just simply identify and follow good authors and cherry pick the posts that they want to upvote. Some openly have bots that auto-upvote who they deem good authors.
If you're a whale with say $0.5m- $1m worth of SP, it makes no sense to think like a small time hustler and indulging in nefarious activities for a few thousand extra dollars. The rational whale would either work to make the platform ultra successful or power down and take their money... rather than risk throwing it all down the toilet for small change.
RE: Blog rewards CAN’T be widely distributed