Are we going back to Client Server technology

I was just reading about Parse, a new startup on Techcrunch. There's kinvey that is doing similar stuff. While the idea is cool and definitely brings speed to creating mobile apps. But I feel we are going back to client server, except this time the client is Mobile. For now they are offering APIs or SDKs which let you store data in the backend without ever building a backend yourself. My guess is they are using key-value data stores that enables dynamic creation of data and attributes. They also offer APIs that let you build a query to fetch the data.

The problem with this approach is i.e not owning backend piece, soon your app will need some kind of backend business logic and not just data storage/access APIs. And when this logic is needed you will be left with no choice but to build this on the client, you mobile phone. So if you building for multiple mobile platforms you will have to replicate this business logic across all clients. Not very efficient in terms of cost, developer resources and time. This is exactly the reason why client server technology failed and could never scale.

While this may still work for apps (games may be) that are light on backend-logic, I feel there will be some duplicate work that will still be done if you develop across multiple mobile platforms.

Not sure how other folks feel about this.