Thanks.  Yes, one way to think of it is as a linux file system with file permissions defined in a smart contract.  Sounds pointless right?  I'm not so sure.  I think there are benefits that could be valuable to DApp developers:

From a DApp perspective the permissions are separated from the data which allows the data to be stored anywhere and the DApp to control access permissions using a state driven, auditable, authenticated smart contract that can accept money.  This opens up interesting new use cases like data monetisation and users taking control of their own data.  It also means the DApp developer doesn't need to deploy and configure their own backend server, instead they simply deploy a smart contract and use an existing cloud based vault server or allow each user to choose where their data is held.

For old-school users and businesses it could be seen as a stepping stone towards full decentralisation.  i.e. businesses can start exploring DApps without having to fundamentally change their existing infrastructure.