Go is one of the few Google things that I will actually use and promote.
I completely understand your justified fear of putting so much stake into a company owned language. It is completely reasonable.
But, since Go is only indirectly benefitting Google (as most of their non-ads products do) then I do not feel that using it is contributing anymore to Google's bottom-line or control than visiting an arbitrary website that uses Google Analytics, or using an Android phone, etc. will do.
But, an important discussion for the Go community (and any company-owned language) to have would be one around the hypothetical of Google shutting off it's contributions to the language.