It's less about documents being managed by conventional office suites and more about sharing documents through Google Docs as opposed to a corporate intranet (and I've seen ones much better-managed and worse-managed than Google Apps).

But the insecurity of desktop document suites doesn't give Google a free pass on having lax security standards.

Of course, this is my evaluation. You and your organization are welcome to use Google Docs if you are comfortable with their security practices.