The ToS provide the binding right for the user to have the video hosted. It's in the name "terms of service": you follow the terms and in return you're provided with a service. In this case, the plaintiff complied with the terms but was denied service. The court didn't approve of that. I doubt it has anything to do with their political alignment.
You're probably right. I assumed that there is a clause in the AGB permitting Youtube to in general not host a video if they don't want to. Or that there is something creating a Hausrecht in there, given them the right to chose a customer. Doesn't seem to be the case.
