The devs feel that curation rewards should favor exploration, and I tend to agree. Ask yourself this: why should people who vote for @charlieshrem get anything? Everybody knows that his posts are going to be popular, so it's a waste of money to pay people to "find his posts."
The problem is that decreasing rewards on popular post doesn't achieve the intended effect, people still upvote these posts and these post are still getting the bulk of the money. So now we end up with an even bigger problem which is that curation rewards are extremely low on the platform.
If devs want to favor exploration , letting authors decide how much they give to curators is the best way to do it imo.
It's true. I've always been disappointed that the website gives absolutely no feedback to voters about how curation rewards work, so incentives only do something for people with the time and expertise to dig into the source code.