>> Pots and kettles spring to mind.
Not exactly. Facebook is a social network and it has always been that. Users should have been aware that by creating a Facebook profile, you were signing yourself up to a social network.
Google, on the other hand, is trying to exploit its monopoly in search combined with their popular mail product to force users into a social network. Forcing users to use Google Plus is against the very grain of Google's slogan and supposed philosophy.
I think you can compare this to Microsoft forcing new users of their OS to use Internet Explorer as a first step.