Sgt_Kickaxe - 6:52 am on Mar 4, 2012 (gmt 0)
I think it has more to do with the fact that sites like pinterest and services like luminate are using the K.I.S.S. method as compared to Google's harder to implement tools.
It's becoming obvious that Google's +1 didn't close a hole in people's desires, it just plugged the hole in Google's(spy?) portfolio.