Earlier quoted context omitted.
That is a very US-centric view of free speech. In many other (developed, democratic) countries, a lot of the shit 8chan does would be viewed as incitement to violence, hate speech, and/or invasion of privacy. The absolutist conception of free speech in the US is an outlier.
If those activities are crimes in a country, then prosecute the crime. It shouldn't be up to a random middle-man like Patreon to be judge and jury and make those (sometimes very difficult) decisions. It's akin to my grocery deciding to not sell me an apple because I'm a suspected murderer. There are better and more formalized methods to deal with violations of social norms.
If a someone shows up and orders 5 tons of ammonium nitrate in December and want's it shipped to Washington DC that's very much a reason to decline and possibly contact law enforcement even as a private citizen. Similarly, free speech has never been an invitation to say anything in any way at any time.