That is the bane of a large company. A product that would've been successful user-count-wise and revenue-wise for a smallish startup starts looking like a failure when you operate in billions of users and tens of billions of revenue.
It's not that someone internally calls it out as a failure, but the constant pressure to compete for scarce resources (department budgets and developers in Google's case) encourages the internal politicking and resource wars. If YouTube or Search or Android is considered top priority at the moment, it's very unlikely some project like Google Voice or Google Talk have any kind of leverage in defending their budgets and/or teams.
It's not that someone internally calls it out as a failure, but the constant pressure to compete for scarce resources (department budgets and developers in Google's case) encourages the internal politicking and resource wars. If YouTube or Search or Android is considered top priority at the moment, it's very unlikely some project like Google Voice or Google Talk have any kind of leverage in defending their budgets and/or teams.