Hmmm, I found this http://www.thewire.com/technology/2011/10/how-survive-switch... which talks about Google ending the Reader social features as of the end of October 2011, sort of in favor of Google+ but that wasn't done well/thought out; I can't figure out if it was out of private beta by then.
So the narrative of at minimum neglecting Google Reader in favor of the not a substitute of Google+ would seem to be correct.
And yeah, at the time there was discussion about how they should have kept reader and somehow rolled it and its users into G+. Reader was their only organically successful social sharing product.
During those years, they let Reader languish, it was treated as a dead project, then finally shut down. So it felt like a continuous series of events.