It seems plausible that lazy voting is identifiable as a user-specific signal, and that lazy voting (contrary to the welcome message
"don't be rude or dumb in comment threads") is a big part of the reason why comments that don't fit the community culture stay so visible. May I suggest that it may also be possible to identify good comment voting (upvotes on comments that link to reliable sources to answer questions, or that say "I'm sorry" or "thank you" as part of a comment) as a user signal? It will be interesting to see what happens to comment scores over time if more overt thoughtfulness (in all senses of the word "thoughtfulness") is upvoted often and comment rudeness or stupidity are (net) downvoted as the software tweaks are implemented.
P.S. I have been puzzled by a downvote and upvote pattern I seem to be observing in this thread itself, with of course only my own score on my own comment being DIRECTLY observable to me as I revisit this thread from time to time.