>Or a highly pacified citizenry?
That's still a war, just a very one-sided war.
>What role does Youtube have in making a kumbaya kind of experience?
I'm assuming the question is "what reason does Youtube have", since their role is pretty clear: they control the platform. If they want people to keep using it, they have to keep those people happy. If they want to prevent a revolt, they have to keep people happy. Because unhappy, unstable people can turn violent. Keeping them happy won't necessarily stop all unstable people from turning violent, but you certainly do maximize that risk when you have some unstable people in your community and your community is already on the brink of a user revolt.