Tons of news, commentary, and furor about the use of real names on Google+ over the past several days.
I think there's a simple reason for the Real Name Rule: it grows the social graph faster. You might know your closest friends by their Twitter username or other online nicks, but the serendipity of connecting with old friends, new acquaintances, and public figures is much easier when you see their real names because that's how you know them. Can you imagine if Facebook showed your suggested friends as johnny411, BIEBERFEVER1997, and SniperKILLA?
Real names are how most of us interact in real life, and that's what Facebook brought to the Internet as a standard practice. Google wants to duplicate that success.
The end game, of course, is money. But not because Google is interested in building ultra-deep consumer profiles or track what you do (to do so would seriously undermine pretty stellar consumer trust in Google to date). They just want their new product to be competitive against the #1 behemoth.