He said "this" experiment, not "the fediverse" which I interpreted to mean his instance (or perhaps Lemmy).
That said, I'm honestly curious what do you care about his "toxicty" if he's not an admin of your instance? You don't seriously believe you have a right to dictate what he does with his own hardware do you?
Eh, I think you're projecting. He literally owned his instance. He was playing with his own ball at his own house and you got "butthurt" because he didn't want to play with you.
It's no secret that a lot of people are attracted to Lemmy because they felt Reddit mods were too overbearing, but some of us like Lemmy because we didn't think Reddit mods were doing enough about the overbearing users.