I suspect that if we imposed a norm on LW that said: every time two people disagree, they have to write down, at the end, why they disagree, we would do better.

Unfortunately that is usually 'I said it all already and they just don't get it. They think all this crazy stuff instead.'

Just letting things go allows both to save face. This can increase the quality of discussion because it reduces the need to advocate strongly so you are the clear winner once both sides make their closing statements.