Chomsky starts the entire chain and every subsequent email with some equivalent of "we don't have enough common ground on these subjects to have a reasonable conversation, so let's not have a stupid back-and-forth in which we do nothing but loudly contradict each other's basically axiomatic interpretations".
And then there's a lot of back-and-forth that's frustrating to everyone involved (and particularly to the third party reading the exchange). It's frustrating because Sam and Noam are talking past one another, and clearly don't have enough common understanding to take part in a productive discourse, and one party is trying the entire time to just get out of the damned stupid back-and-forth of nothing but mutual contradiction.
To me this reads like a very common occurrence at parties I attended in college: two people who disagree, with one person trying to avoid a public argument that's bound to be fruitless and irritating to all involved, and the other one insisting on having the argument anyways. I never had much sympathy for the Sam character when the Noam character finally snapped and told them to change the topic or fuck off.
> so full of themselves that they don't entertain anyone challenging their ideas.
There's a HUGE difference between realizing a particular conversation is pointless and refusing to have any conversations with dissenters. The latter is arrogance, but the former is an important social skill.
> to a genuine offer of conversation...
1. Noam's primary complaint is that he doesn't believe this is a genuine offer of conversation, and that even if it were, he doesn't think the conversation would be remotely productive.
2. Noam has far more patience in this thread than I or most people would've displayed. I probably wouldn't have replied beyond the second email with anything other than "We obviously disagree on some pretty basic facts. Any further conversation on this matter would therefore be fruitless to both of us. Have a great day!"