I don't understand that line of thinking actually (that people should reply when they downvote). Do you get upset if someone upvotes you but doesn't not reply? It seems they are done for opposite reasons.

Some of the reasons I upvote:

  - I agree w/ OP

  - I appreciate the time taken, or the thoroughness of the response/post

  - I appreciate that the post adds to the discussion

  - I appreciate that OP was able to ask a question in a nice way

  - I feel someone has added something significant

  - I get a cheap laugh that isn't terribly pun-y

  - I had too much coffee that day

Some of the reasons I downvote:

  - I don't agree w/ OP and I think they are either wrong are spreading misinformation

  - I think OP is using FUD or other "techniques"

  - OP has included a lot of hyperbole

  - OP responded without being kind, thoughtful, or thorough in the response

  - OP made a blanket statement with no citation ("Blue is clearly the wrong color. Period.")

  - OP did not add anything significant ("+1 here too")

  - OP went for a cheap laugh with pun-y, low-wit, or over-used memes ("That's what she said!")

  - OP posted something that I feel is not HN-worthy or against the guidelines

  - I had too much coffee that day

I'm sure there are more on each side. So did you do any of those?