What you have to remember about Google is that engineers are mostly free to choose what teams and projects they want to work on. And there's also a lot of pressure to go promo.
So in the context of the times (I joined Google roughly around when this all went down, but this is not insider information, I'm just speculating) I can imagine how it happened -- it likely became hard to staff the project. It probably became hard to "demonstrate impact" by doing incremental changes on it, and little desire on the company's part to put a major push on launching new features or migrating it to new tech stack etc. etc. People working on it could have transferred to any number of higher impact projects and done better for themselves in the corporate career success game.
No manager would have the "power" to demand that the people involved stay working on the project.
So if it needed technical work, and no product managers saw a future for it, and few if any engineers wanted to work on it, and Google was in the middle of pushing its energies behind G+... It seems inevitable for a project like that to die. It was likely dying internally long before it was killed externally. That's my educated guess anyways.
So in the context of the times (I joined Google roughly around when this all went down, but this is not insider information, I'm just speculating) I can imagine how it happened -- it likely became hard to staff the project. It probably became hard to "demonstrate impact" by doing incremental changes on it, and little desire on the company's part to put a major push on launching new features or migrating it to new tech stack etc. etc. People working on it could have transferred to any number of higher impact projects and done better for themselves in the corporate career success game.
No manager would have the "power" to demand that the people involved stay working on the project.
So if it needed technical work, and no product managers saw a future for it, and few if any engineers wanted to work on it, and Google was in the middle of pushing its energies behind G+... It seems inevitable for a project like that to die. It was likely dying internally long before it was killed externally. That's my educated guess anyways.