There's a business opportunity out there for someone to build a "Google Backup" tool. It would synch your G-drive to Dropbox, your Gmail to yahoo mail, and so on. Marketed as "in case they turn evil" and intended people like you (and me!) who have this concern.
The company would become useless if Google ever fixed their customer service problems ("they closed my account and wouldn't say why!"), but Google has demonstrated they WON'T fix that.
It's not strictly an apples/apples comparison, but there are several apps like Spanning Backup(1) on the GApps Marketplace that offer whole-account backup.
The company would become useless if Google ever fixed their customer service problems ("they closed my account and wouldn't say why!"), but Google has demonstrated they WON'T fix that.