Hi Eric, great discussion.
On my side, I don't think many users are too cautious about publishing anything because of the impossibility of deleting something.
For sure, these people exist, but I have the impression that the sensation that this community is better comes from the other two points you mentioned here.
The fact that notes can be zapped incentivizes making them the best possible. Although people disagree on what is "best possible," they end up finding a niche of people that like what they like, or they give up.
But most of all, the fact that #Bitcoin mentality is the standard here, at least until now, creates a better place for plebs.
At last, I feel that Nostr needs to go beyond just chilling Bitcoin and itself, to be more compelling to others, but that will come naturally with time.
Have a great evening, sir!
Horns up for Satoshi!