I wrote about this a few years ago, when Wil Wheaton tried to move to Mastodon, and promptly got booted from his instance by a mob.

The "heavy moderation" of IRC days is markedly different than the "heavy moderation" that exists today. Back in the day, the ircops had all the power of the ban hammer. Today, the mob has all the power, and overwhelm the admins.

The mods try to hold onto a semblance of power by pointing to a strict set of rules and codes of conduct, but the reality is the mob gets the final say in who stays or goes, regardless of what the "rules" say.