I see the one selling point of Steem, that cannot easily be corrupted by money, is the free speech aspect. By making downvotes a bonanza for the wealthy - we risk removing that strength. People who say that downvoting isn't censorship are right on a certain level, but wrong on another. Messages get promoted online primarily via social media and advertising on social media - so, often, those with the most money get heard the most. Downvoting removes reach from messages/people and will be weighted more in favour of those with the most money if they get extra downvote power in relation to stake. If downvotes just removed rewards then it would be less of an issue, but they currently also limit reach. Maybe UIs would be developed to incorporate the ability to view lists of posts without the effect of downvotes to compensate for this - but it just feels to be the wrong approach here. I feel like this 'feature' is just wallpapering over the cracks.
If the main selling point of downvoting is a way to counteract bots, I think there are better ways to do that.