There was some post about Israel the other day (might have been Google's relationship to Israel or something) where every comment about the war starting last year was highly visible, while every comment about what happened prior to last year was dead.
I'd be careful about generalizing from one case, or even from all the cases you've seen, because people (all of us) tend to notice and put much greater weight on the posts we dislike. (Basically the same mechanism by which painful memories tend to be deeper than pleasurable ones.)
Those contentious threads never last long here for that reason. Reddit is 90% those sorts of heavily moderated comment threads where everyone agrees with each other and those who don't align get removed or downvoted. People can always just go there.
