I think you’re suggesting that the free speech argument is overblown when it comes to online discussion forums, and I agree with that - they can, should and do set house rules.
The problem that Facebook faces is that it has become bigger than government, and so people expect it to obey similar rules regarding the protection of free speech, but Facebook does not have the power to make actual laws, so it is not required to protect free speech on its platform. Free speech is intended to protect democracy from governments that would enact laws to limit dissent. It is not relevant to Facebook.
The argument that a product whose business model is based on artificially weighting communications between disparate groups for profit and engagement should protect peoples right to inject whichever provocative messages they want into it in the name of free speech seems like a perversion of the principal to me, because the result is an erosion of democracy and human rights as we have seen.
They absolutely should ban people for posting stuff that doesn’t align with their brand, and in a free market those people can find another forum for discussion with more permissive rules. Preferably an open, decentralised network that does not rely on ad revenue or have any incentive to automatically promote the growth of groups of algorithmically selected like-minded individuals.
And yes, I am ignoring all the good things about FB here. I don’t believe Facebook has amounted to a net good for society, however good its intentions.
I agree but that wasn't the analogy I was going for, Facebook's (and Twitter's) main issue is the propagation of non-private communication. If the angry mob is meeting at your cafe and everyone in town knows they are meeting there and what they are doing then the microphones etc. are not required. The privacy issues are mostly orthogonal to the disinformation and bad-for-society stuff.
You pick a cafe. I'll pick the phone company. Would it be out of line to ask phone companies to reconsider allowing mobs to use their services?
(Let's temporarily ignore the legal position phone companies have - they are explicitly protected by the law and not held liable).
The phone company isn't calling me up and telling about about all the stuff the angry mob has been up to and inviting me to join in on their next conference call.
We can trade analogies. And figure out where Facebook should lie, on the spectrum of analogies.