Youtube is blocked in China. So those comments would all be from people paid/forced by the Chinese government to create pro-Chinese propaganda on foreign news and social media.

Might want to note that this is seven months old. Many of those comments are made by what are referred to as "wumao" or "50 cent army" (although now they're more ultra-nationalists rather than paid individuals). That said, you can't outright dismiss them as that is partially their goal. When we stop listening to views that don't gel with out own — or worse, censor them — freedom of speech dies.