I want to start off by saying that I strongly respect John De Goes and the decision he made. If you haven't already read his extensive post about what he did and why he did it, I highly recommend you take the time. His post is thorough and generally persuaded me to his way of thinking, which is not that the works of Moldbug should be accepted or ignored, but that we need to be inclusive of differing beliefs in a community, so long as the holder of those beliefs is willing to "leave them at the door". This is a strong, intellectually defensible and consistent position.
However, as the day has gone on, and I've discussed this issue at length with many members of the community. I have come to the conclusion that this is idealistic, and ultimately missing the point. And as strange as it seems, the point is not that there is a literal Neo Nazi who will be speaking at a well-regarded conference! The point is somehow bigger than even that, and it has to do with community.
Community is everything. I'm fond of saying that programmers are not automata, and that's true, but it radically undersells how important people are. Every time you "do the hallway track" at a conference, you're explicitly making the claim that the people at the conference are more important than the content. People often talk about how you should try to choose your workplace for the coworkers, not the problem. And when we punch our pillows in frustration after a difficult day, we're rarely thinking about a thorny technical problem or an annoying technology: we're thinking of a person (or persons). Community is everything.
And community is being disrupted. Not even by Moldbug himself, but by the idea of Moldbug being accepted in any form. I called this the "meta-controversy" on twitter, and the more I think about it, the more I've realized that it's the only controversy that matters in this case. Community is disrupted by Moldbug. It is now being disrupted by the announcement that he will be speaking at LambdaConf, and it will (presumably) be even further disrupted by the actual event. People are divided, some of whom believe that we can (as a community) divorce ourselves from these ulterior associations and judge solely on technical merit, and others who believe that allowing Moldbug a platform on any topic is benefiting and supporting his philosophy.
What I'm realizing is that it doesn't matter which of these opinions holds sway. The division and disruption of the community itself is the problem, and it needs to be rectified. This would be true whether Moldbug were the second coming of Hitler or of Ghandi. Social equillibrium is tremendously important, and disruption to that equillibrium is a cancer which the community must stamp out for its own preservation. Moldbug must be the recipient of this correction, not because of his views (which are reprehensible), but because of the effect he has. As horrifying as it seems, the fact that he advocates for literal slavery (and more) is secondary to the impact he has on the community as a whole.
The community must always act for the preservation of its own harmony. And to that end, I believe that Moldbug should be removed from his speaking slot at LamdaConf. All arguments about inclusiveness or the technical nature of a conference are an aside, because the community itself has decided that they are an aside by their reaction.
Why do we assume there's a social equilibrium in the first place to uphold, or that maintaining it would be a proper motivation in deciding these things? Society has never been in equilibrium. I think we can come up with better reasons.
The problem with Moldbug in this case is that you cannot separate the politics from the person or project. The goal of UrBit is explicitly political, to implement the kind of society Moldbug wants to see (UR is short for Unqualified Reservations, Yarvis's blog), a pretty ugly one at that. I would further argue that you cannot isolate politics from technology because technology isn't developed in a vacuum and it's denial to think that we can abstract away the social impact of technology for the purpose of a talk.
So I guess my point is that we as technologists ultimately have a responsibility to make ethical choices to make about the impact of our technology on our world. And by giving Yarvis a platform, we have to ask, what is the impact we are making?