I would definitely like to see some sort of simple ‘karma’ system, even if all it let you see was ‘this player has 3.1 average thumbs up in 10 keys’ or similar.
For one, it would help exclude a few toxic players/griefers. I also think being able to give players a up/down would help take some of the sting out of a bad experience, since a lot of the frustration is just that there’s no recourse.
Such a system could be ‘abused’ I guess, but no more than the status quo is.