Not any non startup company I have worked at used GApps, only small startups. And bigger companies / corporations will use SalesForce, sure. But they will also be using another 20 other vaguely similar enterprise products. Sometimes different ones per department.

I don't doubt your claim, but what terrifies me about this if it's true is how willing companies are to give up all their data, security, etc for Google and company to mine, sell, etc. I would never do that. I just don't get that. To me it's insane to let others have and manage all your data. Doing god knows what with all that precious clear text data and and then not knowing who has access to it once it's in the "cloud". Just crazy.

Gapps for business are not mined by Google. If you don't trust that Google would honor their contractual obligations, that's a whole other issue.