I mean, google + didn't become the next facebook simply because it didn't become the next facebook to enough people. Lets not complicate it, people simply didn't switch. It wasn't some bullshit about real names, or youtube integration, or features facebook didn't have. Facebook just kept critical mass.
Google obviously had an uphill battle trying to steal Facebook's thunder. It was stupid, then, to adopt a Real Name policy and enforce it like dicks instead of trying to differentiate themselves from Facebook.
This ties into YouTube, too. Instead of trying to hamfist their existing userbase into real names and Google+, they could have softselled an automatic, no hassle Google+ account linked to your YouTube account, as is. Instead they antagonized their YouTube base, too. Corporate fuckhead thinking.
Would it have mattered in the end? Who knows, but it was a stupid policy that only put up barriers, instead of trying to go after users who weren't interested in Facebook because of their focus on real names.