You can actually defame presidents and never give a chance for rebuttal in your platform if you want to. That's worse than forbidding participation and happens

You can actually defame presidents and never give a chance for rebuttal in your platform if you want to. That's worse than forbidding participation and happens literally all the time. The president doesn't have a right to participate in a platform that doesn't let him. Some presidents around the world can dictate the contents of their country's media platforms and it's not that great a regulation as you make it sound. I hate Zuckerberg as much as the next guy but I don't buy that argument. If hypothetically he wanted Trump to be reelected and thought it was a good idea to call for every left leaning person to be banned from the platform, that's his prerogative. Nobody is forced to use it and base reality on it. Facebook is not a government, that's why it's so good at it.