Earlier quoted context omitted.
YouTube runs at a loss. If it was spun off from google it would not be viable.
as far as I'm aware nobody has ever shown this, all analysis I've seen that lead to that conclusion are based on ideas that Google pays Tier 1 provider rates for Youtube bandwidth, which is definitely not true (Google is directly peered with pretty much every ISP on earth)
I still believe Google has a LARGE interest in owning it though. Obviously. It's simply maybe not good enough in itself