If you trust them, which it seems like you do, to not sell your information for advertising purposes then maybe thats true.
They’re still sharing your personal information with others. Maybe you trust Google to not use the information stored in your drive for ads or to sell you shit but do you then also implicitly trust every corporation that that give that data to? To you then also trust those companies to always handle and treat your personal information with the respect it deserves for all time?
We provide personal information to our affiliates and other trusted businesses or persons to process it for us, based on our instructions and in compliance with our Privacy Policy and any other appropriate confidentiality and security measures. For example, we use service providers to help operate our data centers, deliver our products and services, improve our internal business processes, and offer additional support to customers and users.
If you’re OK with Google using your personal information to sell you adds or with then selling your personal information directly, then it’s a fine option.
Again, i’s a privacy issue. Some people are OK with giving up privacy for convenience, and that’s fine.