"Had Google+ focused on a metric of “Users who choose to go to Google+ and share at least 2 updates per week“, they would have focused their efforts on delivering value to users rather than popups that drive numbers."

The Google+ foundation is all there -- they already focused on that: it really is the foundation of a brilliant social network, and I prefer it purely given that they don't decimate photos by the horrid overcompression that Facebook does. Their problem now is purely a network problem in that people don't see the point of sharing updates there given that many of the people they share them with aren't there. I fail to see how this example supports what they are saying whatsoever.