I really miss maemo, it was pretty much what you're describing. Being able to rebuild packages directly from the debian archive if I wanted some new software, or patch some system software and put it in my own APT repository, are things I really liked.

In addition to the problems you describe with google moving more core functionality into its "Google Apps" packages, it also means that running android without the google bits is getting increasingly hard. It's missing some core functionality that other non-google apps expect.