I didn't say extremist I said toxic but really anyone who's poorly socialized will go where they're allowed, which in Lemmy terms means general catch-all instances with loose moderation like .world and .ml.
If they choose to migrate to another instance, it will likely be a more extremist instance with poor moderation that has been significantly defederated.
In theory this is how it should work, but in practice the toxic people tend to move to general purpose more laissez-faire places like .world or .ml, which makes de-federating and cutting off 30% of all users a difficult decision for anyone trying to have a community.
The answer is less centralization, but that can't be forced. beehaw.org (for example) made the decision to cut off .world and they are better for it. But they are a large-ish instance in their own right.
This is the first I'm hearing of any issue with it resembling a pentagram, the criticisms I've heard involve the design in general not looking professional, not scaling well, and lacking a unique palette.
I'm surprised there's no fedi version of Facebook but I'm also sure as the fediverse evolves we'll see the return of personal websites but with activitypub-based social features.
This is just the domain name, not the instance itself. If the instance is offline the moderator accounts will be inaccessible even if the domain name is sold.
The CEO comes from the world of crypto and it is a for profit company