It seems, you are trying to decentralize the who world which I think is a) unrealistic b) doesn't make sense. On the other hand, we are trying to solve specific use cases with decentralized applications. For instance Bitcoin implements a decentralized payment network to address a specific use case and our application Streembit implements a decentralized communication framework for humans and machines.
I am perfectly comfortable with disseminating the source via the centralized Github, though it would be nice to have a decentralized source control system. Users trust me and get the source from my repository. Users who don't trust me can fork the software and modify or distribute for themselves from the repo of a trusted person. The source distribution is centralized, but so be it. Once the users have the source/binary via Github the application addresses several use cases in a decentralized manner. I don't see how the centralized source repository invalidates the runtime soundness and robustness of a decentralized payment or communication P2P app. At the sametime, the runtime soundness and robustness of decentralized payment or communication P2P applications seriously affected by the centralized bootstrapping.
<<< All of the so called "decentralized" software is fundamentally broken at the moment. >>>
Quite true, but it is broken, because of the centralized bootstrapping, and not because of the source code is managed by a centralized repository application. I can drive with my car to your place and give the source code to you in person, which will be the ultimate decentralized source code distribution, but the issue I was talking about (centralized bootstrapping) will still exists once you run the software. I am talking about design and runtime problems of decentralized networks, and you have been talking about something different. Anyhow, thanks for the chat and all the best! :-)