[geraltofrivia]

I suspect its because containing Google hinders the web experience for people more than containing Facebook would. People have mentioned in threads here that Capchas would become frequent, Google login (which probably is more common than Facebook login) wouldn't work. The addon would make the browser of an average Joe worse than Facebook containers. And when Mozilla is grasping at straws, trying to win back market share, it'll have to really debate whether or not they would want to go forward with this.

Doesn't help that FB is getting a bad rep these days and its more mainstream to hate on it.