You thinking YouTube is a public space doesn't make it so, even if you put is in italics.
YouTube is a company. It has employees, a business model, and a TOS. It decides what is acceptable content. You are free to patronize another video site if you don't like it.
In the 90s, if you argued your local mall was a public space because a lot of people spent time there and that's where the conversation was happening, you would be just as wrong.