Earlier quoted context omitted.
More than 97% of Google's revenues have always come from advertising (give or take a few percentage points). This goes back to the pre-IPO days. It's all well and good to say that Google is about "pushing the limits of human knowledge," but when you're a public company with a responsibility to generate return on capital, you need to protect and grow the golden goose. Now, it's perfectly valid -- maybe even necessary…
Companies that focus on the thing that makes them money eventually start losing money. You have to focus on the next thing to make you money, not the current one. I'm willing to cut google some slack here though, with the self-driving cars and google glass. Innovation at google isn't dead, it's just not in web app form anymore.
Totally agree that a company should never be in that situation to begin with (hence, my comments about the vulnerability of depending for 97+% of revenues on a single product). But they made a bet on social to be their "next thing" and, in retrospect, many smart people probably would have made the same bet. The bet didn't pay off, per se, but that may have been a function of lateness to market more than a function of strategic unsoundness. (And let's give them at least some credit: Google+ had a unique thesis about social w/r/t groups, and it came to market with a differentiating factor from Facebook. It was not simply the me-too product everyone retrospectively labels it as).
I'm not writing an apology for Google's strategy; I'm just saying that hindsight is 20/20 in this case, and we shouldn't lose sight of that.