Because that is exactly what we have all been clamoring for. Gee thanks Google.
Ok, that is more than a bit dismissive and I shouldn't be as cynical as I am about it but I switched to Firefox for a reason, this crap just keeps interfering. But oh wait, want to watch Youtube.tv in Firefox, oh so sorry you can't because it won't do video acceleration. I remember when you had to run Silverlight to watch Netflix too, that sucked as well.