Seems his prime complaint is that resonating consternation is aggressively removed, giving an undue illusion of peace and harmony - and somehow that's a bad thing.
Some issues are social hot buttons, with a roughly even split (if not in actual numbers, then in energy exerted in pushback against the opposing view), roughly equal validity to each perspective, and pretty much no chance of one side reversing their view en masse in short order. Repeated prolonged verbose heated arguments over these subjects will not lead to any meaningful consensus. Their presence tends to erupt as a tangent or non-sequitur to another discussion, destroying the overall thread in a wave of verbose hysteria. Nothing is served by their recurrence; we all know there's a dramatic split on views regarding the subject, we are each settled in our own views thereon, and frequent re-hashing the subject just sours the environment and encourages participants to seek more sensible discussions elsewhere. Ergo, there's no point in letting these recur. PG is right in weighting the algorithm so such destructive & pointless discussions tend to disappear.
Yes, we know such disagreements exist. A policy of "not here, guys" is a good thing. Yes, the issues being suppressed are of great sociopolitical importance; please recognize that decent people can disagree over them, please agree to disagree, and resolving that disagreement will not happen here - but continued rehashing thereof will create a toxic environment.