a confining idea of a "public sphere"

Statements such as this one from libertarian pundit Brendan O'Neill (in the wake of the Alex Jones purge by social platforms) are common on both the left and the right:

For good or ill, the social-media sphere is the new public sphere. The expulsion of people from these platforms is to 2018 what a state ban on the publication or sale of certain books was to 1618. How can we convince the owners of social media to permit the freest speech possible and to trust their users to negotiate the world of ideas for themselves? This is the question we should be asking ourselves, rather than concocting more ways to encourage these corporate overlords to censor and blacklist.

O'Neill's main complaint in the essay is that "radicals and liberals" (i.e., the left) approve free speech suppression by platforms:

We live in strange times. On one hand it is fashionable to hate capitalism these days. No middle-class home is complete without a Naomi Klein tome; making memes of Marx is every twentysomething Corbynistas’ favourite pastime. But on the other hand we seem content to trust Silicon Valley, the new frontier in corporate power, to make moral judgements about what kind of content people should be able to see online. Radicals and liberals declared themselves ‘very glad’ that these business elites enforced censorship against Jones and Infowars. We should be ‘celebrating the move’, said Vox, because ‘it represents a crucial step forward in the fight against fake news’. Liberals for capitalist censorship! The world just got that bit odder, and less free.

Yet O'Neill also cedes power to platforms when he calls them the new public sphere. People can and do quit Facebook and Twitter. A large infrastructure called The Internet still exists outside platforms. Jones got his start in that infrastructure and it's still available to him. He wasn't denied funding sources (a la Wikileaks and Paypal) and the servers hosting his websites haven't been shuttered. People have gotten lazy about letting Zuckerberg et al "do it all for them" (web hosting, photo uploading, managing mailing lists). All these activities can still be done outside corporate-managed "social."

Update: After this was written Alex Jones got de-Paypalled. As a friend noted, the establishment must truly be worried about revelations of demons and lizards at the highest levels of government.