Full disclosure - I work for nanobox.io, a company that is trying to do this.

Deploying a "Docker application" is complicated, especially when you throw things like K8's into the mix. Container networking and communication isn't easy.

You're right though, it does make sense for there to be a service that does this, and thats why there are things like flynn.io, dokku, and nanobox.io, each trying to tackle this problem and make creating and deploying docker applications easier.