I like the idea but it seems like it works better in theory. Unless someone can really streamline the entire process (sharing, security, hardware upgrading etc) it seems ambitious that millions of people would want that kind of responsibility.
I want to work on this idea to make it into a company. I am kinda soliciting ideas from people to learn more. I think the this product will be useful precisely when all the issues you mentioned will be streamlined. A simple web based UI to the homeserver can allow for installing apps, removing them, setting up passwords, uploading data and consuming data from within the house network.