[Someone1234]

On HK the downvote button is in fact an "I disagree" button (or more specifically that is one valid use of it). See:

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

[Smithalicious]

I stand corrected then. Not a great move from me to correct others on what the downvote button is for without even knowing myself...

Of course, when asking whether or not I think a downvote should be a disagree button, my answer is a resounding "NO!".