Personally, I get far more value from G+ than I do/ever have done from twitter, Facebook, MySpace, or any of the many social networks over the years. I have a use for it, which it fulfills better than any of the other services out there, and so for me (and the thousand or so people who I'm connected to at various levels through G+), it's far from a waste land.
G+ isn't for everyone, and that's fine. It is a product which is now highly polished, and provides exactly what I and many other people have wanted from a social network. The exact numbers of users who actually actively use it may not be clear, but if it was a waste land, Google wouldn't be integrating all their services so tightly into it.
Google is not a stupid company, and they're not about to "break" all of their services to drive adoption of a service which can't stand on its own. G+ is a good service, and is providing massive amounts of value to Google. Reader was not creating new value for them; wave wasn't getting adopted; Google had reasons why continuing to support those products was a losing bet.
They are integrating so many of their services into G+, that you can pretty much guarantee that it's a winner (for them, at least).
</rant>