Suppose a private entity does not want to broadcast a view it finds objectionable. The state, by means of the law and its penalties, says that the private entity must broadcast it. The private entity broadcasts the view. Why, under your framework, has the private entity not been compelled?
Because that company can now admit that they will be responsible for any and all content on their website, as they are curating it based on the viewpoint. Something Youtube execs insist (including under oath in front of Congress) that they don't do. You want companies to declare they are non-profits to avoid taxes, and then not follow the rules for non-profits? I have no problems with Youtube declaring that it has decided that no opinions other than its approved ones are acceptable on its platform. And then it should lose any protections it receives for not being a publisher.
Obviously, private entities are not compelling anyone to post on their platform. I am asking why you feel they must broadcast views they don't want to broadcast under threat of being treated as a publisher. See below.
Because that's the definition of publisher.
I understand that you believe platforms have gone too far in moderation. How does classifying them as publishers lead to less moderation? If, under your asserted legal regime, platforms are now liable for their content, won't that lead to more aggressive moderation and banning, not less? Legacy publishers all place substantial editorial boundaries on what will or will not be published. How would classifying social media as a publisher lead to a different result?
Because Youtube has reached near-monopoly status by leveraging legal, financial, and social protections afforded it by claiming it is not liable for the content posted (note that copyright strikes are totally a Youtube invented process to avoid liability for Youtube under the DMCA, and exist nowhere in the legislation itself. And this quasi-legalese processes are then presented as if they aren't also used by Youtube to pick and choose content to approve/reject. It's the same thing with respect to moderation.). I haven't said anything about this leading to less censorship (though I would like less). It will result in Youtube no longer leveraging legal protections to dominate the market and allow the potential for more competition. which may result in less censorship. There is a chance, whereas now there is none.
Who do you propose should enforce this demand?
Are you dense? No one needs to enforce it. Those opinions need never be posted by Youtube. Just, the next time someone wishes to sue Youtube for viewpoint discrimination or other issue, depending on the laws involved, the courts simply won't absolve Youtube based on the fact that they are feigning viewpoint neutrality and claiming whatever legal protections come from it, if any. I have no problem with Youtube being held to the same standards as every other publisher. You need to explain why they shouldn't.
Amusingly enough, this entire discussion proves my point. Here we have a bunch of internet randos "sucking the dick" (as you accused another poster of) of the largest internet media company on the planet, and who I guarantee would lose their minds if Youtube decided that LGBT or racial issues were inappropriate for a corporate brand to be promoting. And yet, you would empower them to do that, while giving them government protections while doing so. The assembled wisdom and foresight of these internet Nostradumbasses, were it converted to water, couldn't drown a microbe...