Why does it matter what others on HN think? Either you find a comment insightful, read it, upvote and move on. Or it isn't, or maybe it's outright wrong, and you try to correct it. Or you found some question in your head, so you ask that.

Not once have I wondered what "HN at large thinks" because it simply doesn't matter. What HN-the-collective thinks about things-in-general just isn't interesting, people's individual thoughts and opinions though, is so much more valuable to read and interesting.

Polls would be just as inconsistent as the comments. Individual contributors would be consistent, but different polls would select for different contributors.