The question is not whether it elevates the conversation, but whether this is a sufficient reason for a ban.

I would think that a ban should be based on what you do to the tone of the conversation.

With that said, I don’t see how this email meets that standard.

If someone is consistently debasing the level of conversation then yes, it does merit some kind of action. Unmoderated communities turn to shit very quickly.

These kind of bans are never about "one thing." I'm sure this is just the straw that broke the camel's back, especially given ESR's history.

Merely calling people Marxists would be better than what he actually did, which was calling them a “toxic loonytoon” conspiracy theorist engaging in “political ratfucking” by attempting to “install political officers in every open-source project” as part of a campaign against freedom. Sure, he also mentioned Marxism, and probably associates all those other things with Marxism, but the reference to Marxism itself was probably the least problematic part of the barrage of personal attacks.

The people in question are usually quite proud of being Marxists.