There’s a big difference between a person’s right to publish/distribute their own opinions on their own network and a third party publishing/distributing other’s opinions on the other person’s network.

The owner of the platform has not only a right but an obligation to establish its own standards for its own platform as you do for yours.

Ask yourself, “Would I expect the NY Times to accept my money to publish this in their paper as a paid ad?” If not, then I don’t think you have a complaint if Twitter won’t allow it.

Also, to gain the benefit of free speech you have to be subject to the penalties imposed on unprotected speech (defamatory, invasion of privacy, violation of copyright, using some’s name without permission) which means that there is no right to anonymous speech.