Because no private company should have that much control, we've been down that path and it was bad enough I thought it should be obvious.
Then there's things like adding DRM, a user hostile "feature" google shoved down our throats. Visit netflix on a linux box and you'll discover that "works with chrome" is the new "works with IE".
It works in Ubuntu. Maybe I'm missing your point. It didn't used to work on Linux at all, without jumping through a ton of hoops pretending to not be Linux.
