https://news.ycombinator.com/item?id=16131314
Now if it is reasonable that a designed in "disagree" button is also used for automatic moderation (greying/hiding/easier flagging/etc) I'll leave up to the opinions of the reader.
Multiple sites have implemented some form of upvote/downvote. That within itself is a great proxy for agree/disagree. The problem sites have is when they take a downvote to mean both disagree and low quality/bad/de-modded. HK technically has flag to solve this, but that isn't how the site is implemented.
PS - I didn't vote on the post above at all.
PPS - You should downvote this very post per (last line): https://news.ycombinator.com/newsguidelines.html