I agree that downvoting someone on HN is not censorship.
What I meant is the biases of the people writing and training the ranking / flagging algorithms bleeds through into the implementation. Similar to how there have been stories that facial recognition tools only recognize white people.
I don't know that it's a great argument or analogy. I mainly was trying to point out that when you escalate from individuals downranking items to individuals writing algorithms that have similar built in biases, then you end up with something very near censorship, even if it isn't intentional.
I believe that's really the whole argument behind "system discrimination", maybe individuals aren't overtly discrimination, but the system is built up in such a way that the result is discrimination.
You can agree or not, but it's worth considering, and I'd guess most people could be convinced of it in one context or another.