I suggest a different and possibly better way of thinking about what Eliezer says about "moralizing" and "judging": don't judge other people. Enabling reasonable discussion and being fun to be around depend more on whether one turns disagreement into personal disdain than on what sort of disagreements one has.

(Some "moralizing" talk doesn't explicitly pass judgement on another person's worth, but I think such judgement, even if implicit, is the thing that's corrosive.)