Imagine if all the end user does is install the store, and clicks the link to the project app. The store takes care of the rest. The developer marks their package as an installable program to be published to the store, optionally specifying things like specific platforms if needed. All the project website does for users to install is provide a url to their app in the store. 

Very very rough idea of how it might work: a store app API would provide an installation GUI if desired, and the store would build the environment needed for installing the package and dependencies. Once the specified environment is built, pip would take care of installing the package as usual. 

If this is an awful idea feel free to just say so. I have given it no deep thought and do not have the expertise to even think through what would be needed to create such a thing.