They should just get it
They can be big in a lot of areas. They don't need to be big in everything, and especially in the social media stuff they don't really need to be dominant in that. They might get more success if they allow people to hold on to their nicknames instead of pulling a Facebook and forcing everyone to use their real names. Sure, the whole "social media" stuff is a moneymaker because of the data slurp, but in this area Google doesn't really need to make money, they can simply hang the social media stuff on their servers which do other stuff that does give Google revenue, and keep users' privacy intact.
Come on Google, you can do it. You're already doing ads on GMail, you don't need to slurp ID data!