If the extremes were banned, then the promoted neutral/centrist view would become extremist on it's own. Cross-subrreddit trolling and genuine spills at least

If the extremes were banned, then the promoted neutral/centrist view would become extremist on it's own. Cross-subrreddit trolling and genuine spills at least minimises echo chamber effect somewhat. If that was limited or non-centrist subreddits/users were banned, the centrist (or whatever was supposed to be OK) echo chamber level would go off the charts.