From my paltry observations it seems like opinions about federating with Meta spread into the following:
1: All for-profit corporations bad, so no federation
2: Meta bad, so no federation
3: Meta bad, but wait & observe first
4: Growing the influence of fediverse is usually preferred
5: Free speech for all

Honestly the article resonates with me a lot. I assume many old-guards of Mastodon are ppl who are fully aware of how federation works & are somewhat left-leaning and anti-capitalist, so they have a tendency to not want to federate with Meta.

So it certainly doesn't help that a few very influential people signed the NDA to join the Meta meeting, which would almost signal that they are more right-leaning (which is not what most people are like on fedi). Regarding the NDA part: people sign NDAs for too many things in pharma (my undergrad field) so I didn't realize it was such a big deal... I think it probably rubbed too many people in the wrong way.

Also, for large general instances, I wouldn't be surprised if many people have ideological differences with their admin or their neighbors, which probably resulted in some "fun" discussions.

Finally, PSA: I know some people hate their admins now but please do not ever send death threats to people, seriously