What is the difference between a society and a private entity? Are they interchangeable? Does ownership constitute absolute authority? Historically, I know of no such society which has considered them interchangeable so I find it outrageous to act like they are.
The second consideration is what recourse private owners have to disallowed speech. It's not jail or execution. Typically just dismissal.
I do not understand the argument that a platform is not allowed to police itself.