People are much better at not committing the planning fallacy (in the underestimating direction, at least) when estimating other people's timelines for a given task, so I'd say absolutely it's a social thing. There's immense social pressure to give a rosy view of yourself; you wouldn't want to disappoint, would you?
There doesn't seem to be any archive of this particular post, but the comments are intact here at least: https://www.greaterwrong.com/posts/G78CnAYMLbWEDKj6w/diachronic-done-right
(you'll need to open this with copy/paste; LW is too clever and replaces the link's actual URL with lesswrong.com, which doesn't have the comments. Gotta open it on greaterwrong.)
Did the RSS feed ever come about? I don't see it anywhere obvious there.
Responding to this on the point of feelings/bids/etc:
One problem I run into a lot is that I want to just say X, but it's fo freakin' difficult to do so without also accidentally saying Y. The default solution is to put a boatload of effort into crafting what I'm saying to evoke the correct response in the other person, but this is difficult and failure-prone. So if we don't go that route, in order to communicate what I mean to communicate and not also something else, it takes some cooperation between both parties — I promise that I just mean what I'm saying, and not other possibly-inferable implications, and the other party agrees to take what I say at face value. (And if any implications come up that seem important, assume they aren't attempts at manipulation, by default, and ask about them directly if you want to know what they think of that unsaid thing)
Actually doing that is difficult for both parties, but when both give it a good effort it enables some things that are super difficult to communicate otherwise, and I suspect doing this frequently makes it much easier with practice.
I'm pretty disappointed in how hidden the San Francisco event was. I was looking forward to the possibility, but nothing on Google or even Less Wrong gave any indication that it existed (except in the hypothetical and previous years). I was sad to discover after the fact that there was one, but I /still/ can't find details for it.
Here's an Archive.org copy of the broken Method of Rotation/Kierkegaard post