It was only a "mass exodus" in the minds of Carl Benjamin fans. In reality he was a notable individual but ultimately a drop in the bucket relative to all the other activity on Patreon.
Regardless of if it was a drop in the bucket to their revenue, their probable acts of tortious interference could cause material arbitration costs to them for deplatformed creators that chose to open arbitration cases against them: https://www.cernovich.com/patreon-mandatory-arbitration/
It seems they made the decision that they just didn't want that style of content on the platform – Benjamin, Harris, Peterson, etc, and the controversy, or risk of controversy that went with it.
I've been a follower of/contributor to some people in that sphere (though not Benjamin, to be clear), but I can understand Patreon making that choice and preferring to be a platform for creatives like musicians, filmmakers, writers, artists, etc.
Controversy seems to be a euphemism for "wrong" political views though. I'd be more sympathetic if they had a blanket "only creative professionals" policy.
It's not a political issue, that type of language is not acceptable anywhere in public society; even 30 years ago you couldn't speak like that and expect to retain any position of prominence. Try that here and you'd be banned very quickly. Patreon making the decision to explicitly rebuke that kind of language seems totally within the realm of defensive corporate PR.
