I have this little pet theory:

There is a loose, inverse correlation between money and empathy. To put it simply, if you have have a lot of money (i.e., you're a whale), empathy for others is less of a requirement for satisfaction in life. Or to put it differently, a whale has no need to care about the plight of others since money seems to separate the whale's fate from those less fortunate.

The following passage from your post, at least to me, correlates well with my little pet theory:

The current problem with Steemit is that the major SP holders have no reason to waste their time curating posts or otherwise spreading out the reward pool.

Even if all upvote bots disappeared tomorrow, that's not going to change the fact that these accounts have virtually no interaction with the bottom 95% of the community. (*emphasis mine)

Until the whales get it that their fates are tied to those of the minnows, nothing is going to change. The only sure fire way to deal with the problem is to consistently post quality content. There is also evidence that recent programming changes are flattening the reward distribution and making it less profitable for a whale to just sit on his SP. That could make a difference.

I suppose the key question here is: What is the payoff for a whale to believe he has no need to interact with minnows (or plankton for that matter)? I don't think it is just "saving time". I think it is about status. Now I could be totally wrong about all of this, but I've seen at least one whale play the "you're just jealous" card and it was not pretty.

I like your ideas, but given the stats you just provided, buy-in from whales will be difficult at best to find. Good luck.