I think my peers would factually right, at least directionally, in that attending with someone who has controversial views is evidence of favoring those views.
As for whether society is a better place if we enforce the norm, I think there’s a couple relevant considerations. The first is the degree of abhorrence. To pull Godwin’s Law, I think that knowingly attending a conference with literal neo-Nazis should be seen as support for their views. The second is the degree of focus. Where it should be fine to attend an academic conference with subject matter experts talking about their work, choosing to attend a “fun forecasting-adjacent festival” where attendees are encouraged to pal around with each other is more deserving of judgment.
I would also like to clarify, when I talk about peer judgments, I’m not making a point about how Manifest looks to those people. I’m making a point about how it would feel for them to attend. While I understand there are tradeoffs involved and you can’t make the event welcoming to arbitrary potential attendees, I would say by the time you’ve lost Peter Wildeford you’ve gone too far. I would also throw my hat in the ring as someone who works on prediction science and would be hesitant to attend the next Manifest if it had a similar invitee list.
I’ve made a similar point in other comments, but this framing makes things worse. Then it’s not that Richard Hanania has relevant expertise in spite of his controversial statements, it’s that you think he’s a fun guy that you’d like to hang out with. Where people are willing to stomach unsavory co-attendees at a conference in their field, they’re more than happy to skip out on a scaled up house party with them.