Seems to me we have to differentiate between two things:
a) x-rationality (rationality without compartmentalization)
b) LessWrong x-rationalist culture
Rationality means thinking and acting correctly, not doing stupid stuff. Culture means creating an environment where people feel comfortable, and are encouraged to do (what the culture considers to be) the right thing.
There is only one rationality, but there can be multiple rationalist cultures. Different cultures may work better for different people. But different people cannot have different definitions of rationality.
Seems to me that polyamory is a clearly cultural thing, atheism is a part of rationality itself (not believing in magic, not accepting "mysterious answers", reductionism), and cryonics is... somewhere in between, these days probably more on the cultural side. Secular solstice is obviously a cultural thing, and in my opinion not even a central component of the traditional LW culture; although it's obviously related.
I love the "old good hardcore LessWrong rationalist culture", and I would be sad to see it disappear. I want it to survive somewhere, and LW seems like the logical place. (I mean, where else?) But I don't want to push it on other people, if they object. I enjoy it, but I can understand if other people don't. I support experimenting with other rationalist cultures.
Not sure what is the solution here. Maybe making the cultures more explicit? Giving them names? Yes, this encourages tribal thinking, but on the other hand, names are Schelling points. (And if we don't have an explicit name for the culture, people will simply use "the rationalist community" as a name, and then there will be confusion when different people will try to define it differently, when what they really mean is they prefer different cultures.)
Actually, this could be an interesting topic for a separate discussion: Do we need a rationalist culture? What kinds of cultures (that we could consider rationalist) already exist? How to design a new one?
Cross Posted at the EA Forum
At Event Horizon (a Rationalist/Effective Altruist house in Berkeley) my roommates yesterday were worried about Slate Star Codex. Their worries also apply to the Effective Altruism Forum, so I'll extend them.
The Problem:
Lesswrong was for many years the gravitational center for young rationalists worldwide, and it permits posting by new users, so good new ideas had a strong incentive to emerge.
With the rise of Slate Star Codex, the incentive for new users to post content on Lesswrong went down. Posting at Slate Star Codex is not open, so potentially great bloggers are not incentivized to come up with their ideas, but only to comment on the ones there.
The Effective Altruism forum doesn't have that particular problem. It is however more constrained in terms of what can be posted there. It is after all supposed to be about Effective Altruism.
We thus have three different strong attractors for the large community of people who enjoy reading blog posts online and are nearby in idea space.
Possible Solutions:
(EDIT: By possible solutions I merely mean to say "these are some bad solutions I came up with in 5 minutes, and the reason I'm posting them here is because if I post bad solutions, other people will be incentivized to post better solutions)
If Slate Star Codex became an open blog like Lesswrong, more people would consider transitioning from passive lurkers to actual posters.
If the Effective Altruism Forum got as many readers as Lesswrong, there could be two gravity centers at the same time.
If the moderation and self selection of Main was changed into something that attracts those who have been on LW for a long time, and discussion was changed to something like Newcomers discussion, LW could go back to being the main space, with a two tier system (maybe one modulated by karma as well).
The Past:
In the past there was Overcoming Bias, and Lesswrong in part became a stronger attractor because it was more open. Eventually lesswrongers migrated from Main to Discussion, and from there to Slate Star Codex, 80k blog, Effective Altruism forum, back to Overcoming Bias, and Wait But Why.
It is possible that Lesswrong had simply exerted it's capacity.
It is possible that a new higher tier league was needed to keep post quality high.
A Suggestion:
I suggest two things should be preserved:
Interesting content being created by those with more experience and knowledge who have interacted in this memespace for longer (part of why Slate Star Codex is powerful), and
The opportunity (and total absence of trivial inconveniences) for new people to try creating their own new posts.
If these two properties are kept, there is a lot of value to be gained by everyone.
The Status Quo:
I feel like we are living in a very suboptimal blogosphere. On LW, Discussion is more read than Main, which means what is being promoted to Main is not attractive to the people who are actually reading Lesswrong. The top tier quality for actually read posting is dominated by one individual (a great one, but still), disincentivizing high quality posts by other high quality people. The EA Forum has high quality posts that go unread because it isn't the center of attention.