Every Google product I’ve used has at some point started getting worse rather than better, if not simply canceled. From search to docs to notebooks to reader to YouTube to gmail, etc. My problem with all the G+ integration with other products not for any privacy concerns but because the result is worse than what it was before.
So, the reason I won’t be buying a Nest or Protect now is not because I’m afraid of Google spying on me. It is because my expectation is that being part of Google will make these products worse.