I'm not sure about it. I think most people are concerned about their privacy 'from' google, not Google's ability to protect their data from rest of the world. If it's the latter, I trust Google. For example, Google was the first one to start voluntarily publishing government's requests as transparency reports, which others had to follow. Even technically, they have done great deal of work (if you regularly read their blogs) to protect my data from unintended parties.

If it's the former, however, then it's arguable and a little subjective so I won't go into that.