I don't like the mob thing either but it's how large group dynamics on the internet work (by default). We try to mitigate it where we can but there's not a lot of knowledge about how to do that.
Are there people whose upvotes count for more than others? Or are these actively suppressed? Either way, it makes it hard to have important/robust conversations when the people seeing them gets suppressed
Re the second bit: there aren't any accounts whose upvotes count for more, but if accounts upvote too many bad* comments and/or get involved in voting rings, we sometimes make their votes not count anymore.
* By "bad" I mean bad relative to HN's intended purpose as defined here: https://news.ycombinator.com/newsguidelines.html. Relative to that, "bad" means snark, flamewar, ideological battle, etc. — all the things that zap intellectual curiosity.
I have a lot of karma and an account over a decade old. So I probably have nothing to worry about. But is agreeing with comments killed by down vote really a red flag?