Negative curation isn't happening not because of a lack of time but because of a lack of balanced incentives between up and down votes.
The rules of Steem for downvotes have to improve to at least account for the lost opportunity cost of curation reward.
I like the idea but this will mostly piss-off the wrong people.
RE: Reminder, GrumpyCompliance in 7 days + Look who's buying votes on his 6 days old posts.