I often seem to run into problems when I use the de facto label for this group. For example, when I say, "I've been hanging out with rationalists lately," I notice that many people immediately go on the defensive. They might ask why you need a group in order to be rational, or they might say that they don't believe that people are inherently rational. Of course, I made none of those claims, I simply indicated that I was hanging out with rationalists.
You might think that "rationalist" is simply a descriptive label, but it carries positive connotations -- and what people tend to hear is "I'm a superior thinker to you," or maybe "I'm a part of this group, which ascribes the label 'rationalist' to itself, to make ourselves seem higher status than we really are."
Why does this matter?
The community doesn't exist in a vacuum; how the community is viewed from the outside matters. As the community grows and as people gain awareness of it, branding becomes important. People talk to each other, and communities gain reputations. Even if you believe that we are a loose collection of individuals, as soon as you assign a name to yourself, that is sufficient to form a group identity.
The people we interact with tend to share similar interests. The population of New York may be in the millions, and yet I run into the same people at different functions without coordination.
The more negative perceptions associated with a group, the more rapidly evaporative cooling of groups will occur.
What to do?
It's far better to talk about good things that you've gained from being in the group. It's better to say what the group does, not what the group is.
But beyond that, it's about time the community picked a better label to use. I have one idea, but I'll hold off on proposing solutions.
The point is that the thoughts are so diverse that the main thing they have in common is their original promotion by a single individual. But it really isn't just Yudkowsky's beliefs that have become currency here. Lots of his idioms pop up everywhere, for example. There was recently a Chuck Norris-inspired thread about how amazingly intelligent he is - tongue-in-cheek, but still telling. And there does seem to be an implicit agreement by many that he's likely to be an important player in saving the world from a certain looming existential threat if anyone is.
I'm a newly-arrived outsider and am doubtless missing tons of context and information. But from the perspective of an outsider like me, it sure looks like there's this one guy who most directly shapes thought and language, who's held in esteem beyond all others and whose initiative provided the glue that holds the whole thing together. That's not to say no one can or does question him. "Yudkowskian" still feels like the single word that best captures all of this.
Also, I'd like to reiterate that I'm not trying to provoke or offend.