See, that's an interesting angle. Facebook had to stick with real names because they were trying to become the default source of personal identity online. (and basically succeeded) But with real identity comes a whole host of problems.

If Google had pivoted 180 degrees and offered up a full featured social network with pseudonyms and, like, one other twist so that it wasn't just Myspace, then there's a reason to care about Google+. LinkedIn is facebook for professional identity... There have to be other identities not shown on Facebook that google could have gone after.