> I can't fathom why anyone would use downvoting as disagreement
That’s often one of the primary uses of downvoting. Here or anywhere else that has downvoting on discussions. What would you use it for? E.g. inappropriate content or content that doesn’t belong is rather flagged.
> if folks want to be in an echo chamber, there are plenty of places on the net for that
Unfortunately that’s most social media. Including HN (possibly to a lesser extent, but still true).
The echo chamber is a feature, not a bug. I choose to spend my social media time in areas that are grounded in objective fact and discuss topics I am at least distantly interested in. That means suppressing the overwhelming majority of things.
I use downvoting for comments that are incorrect, or are in violation of the guidelines. I'll also flag when appropriate, but sometimes flagging feels overly aggressive.
People are right to have both downvoted and flagged your comment - downvoting for disagreement is a perfectly normal part of HN and has always been and complaining about votes is something the guidelines ask you not to do (same with generic community-directed swipes, comparisons to reddit, etc)
