Not every feature is about the NSA nor every upgrade is a "PR move", this is a standard feature that Amazon also offers, and keeping law enforcement out isn't

Not every feature is about the NSA nor every upgrade is a "PR move", this is a standard feature that Amazon also offers, and keeping law enforcement out isn't its main objective although it would make things a bit difficult for them since a warrant would be necessary to get the keys as a court order won't do, but if you are so inclined no one is preventing you from encrypting your stuff before uploading.