That's a bit of a strawman, since the OP didn't talk about the first amendment but about "free speech". Free Speech is a principle coming from the enlightenment

That's a bit of a strawman, since the OP didn't talk about the first amendment but about "free speech". Free Speech is a principle coming from the enlightenment of which the first amendment is one expression, but certainly not the only expression. The idea is that speech should be tolerated even if you disagree with it, and that societies that make room for controversial speech are better off, in the long run, than societies that do not. As a corollary, it espouses the view that individuals should be free to speak their mind and should be tolerated even if their speech is controversial. Because we cherish Free Speech, we created the first amendment. The first amendment is not the sum total of free speech, nor is free speech merely a governmental issue. For example, the California labor protections that protect employees from being fired for what they say in their private time is an example of the principle of free speech at work, and has nothing to do with the first amendment. The principle of free speech is why there are many processes, both private and public, in which the public is invited for individuals to air their views, whether they be question and answer sessions in companies, or local government hearings. It's also the principle behind movements to build public libraries that stock controversial books. Almost every institution, whether public or private, tries to give some room for dissenting speech in its operations and tries to create a space for people to air their views. Thus the attacks on these spaces, even if they are not attacks on the first amendment, are of concern to those of us who value free speech. This includes opposition to efforts at censorship, both public and private, whether these be the circulation of blacklists of communists during the cold war, or any other kind of punishment, both public and private, merely for speech. You may not agree with these values, but merely saying "well, the first amendment doesn't prohibit it, so it's not an attack on free speech" is a wild misunderstanding of what free speech is.