Google is a massive global corporation, it is accountable to its shareholders, no-one else. 37Signal/stripe/github are all small "boutique" companies (Try asking your Mom/some guy from High school what github is) who are privately held. If Google doesn't have checks and balances (management oversight and responsibility), it would fail an audit and the financial regulators would start knocking at the door.

I'd like to know how you would explain to shareholders that you are spending thousands upon thousands of pounds running a service which generates no revenue and doesn't encourage use of its other products ("anecdotally, I don't even know anyone who uses Google Reader directly, they all have dedicated apps." hence no ad revenue or cross selling). It's nice if companies can do this but they aren't charities, this was a piece of charity google had to let go... and now we have a beautiful ecosystem of RSS clients with innovation and variety, I can't remember the last time I saw a monopoly was crushed of the companies choice and a tonne of little grass roots were seeded.