By that argument, the US "monopoly or near monopoly" phone company AT&T during the Vietnam War could have decided that anyone who spoke on the phone about their opposition to the Vietnam War was unpatriotic and canceled their telephone service, and leftists who so often now make the argument you're making would have supported their right to do so. "The private phone companies should be allowed to enforce their terms of service prohibiting anything they consider 'hate speech' against America," explains Noam Chomsky, adding that "I don't share their opinions about the war, but it's not as if the govt-run postal service is doing it, so I don't see the problem."
The two major credit card companies that dominated could have canceled anti-war "haters'" credit cards in the name of patriotic support of the just cause, banks closed their checking accounts, the major airlines refused to fly them, and so on, and those on the left with your principled commitment to the right of "monopolies and near monopolies" to enforce their political preferences would have had no major objections--as long as it really is a general principle and not just a pretense.
Is the government or some other absolute authority censoring wrong? Yes. Are powerful monopolies (or near monopolies) wrong to censor? No, because they have the same speech rights as others
And yet I suspect that this support for the "freedom" of the most powerful to silence, control, and enforce their will is not really the general, politically neutral commitment to everyone's freedom of choice that it pretends to be.
They literally could have if the technology and motivation was there, that's why they were considered a monopoly and broken up by act of the state: because the lack of a viable competitor service means that sort of consumer hostile action was possible.
Of course, in reality phone company's exchange the right to monitor what you say for common carrier status which makes them legally immune to the fact you are saying it, and credit card companies do in fact ditch whoever they want because they have no such burden.
The solution in one case is obvious (protect net neutrality) and the solution in the other case would line up with the calls for US Post to be extended to offering basic banking services to ensure an appropriate floor on the transaction market, and as a government entity would have to allow everyone to transact.
It's not clear to me what you seem to think Google, Twitter or Facebook should get in response for becoming a "public plaza" style arrangement which would be detrimental to their business model and wouldn't destroy the rest of the internet in the process? After all is a DDOS attack also free speech? A botnet? What are we going to obligate them to carry and on what basis?
The two major credit card companies that dominated could have canceled anti-war "haters'" credit cards in the name of patriotic support of the just cause, banks closed their checking accounts, the major airlines refused to fly them, and so on, and those on the left with your principled commitment to the right of "monopolies and near monopolies" to enforce their political preferences would have had no major objections--as long as it really is a general principle and not just a pretense.
Is the government or some other absolute authority censoring wrong? Yes. Are powerful monopolies (or near monopolies) wrong to censor? No, because they have the same speech rights as others
And yet I suspect that this support for the "freedom" of the most powerful to silence, control, and enforce their will is not really the general, politically neutral commitment to everyone's freedom of choice that it pretends to be.