Thanks for the thread and link OP as this is something I have becoming interested in the last few months.
You could also want to build some small centralized blockchain for your small project or even of some company, limitations are endless. Building blockchain is not strictly tied to building next altcoin as money is just one application that can be built on top of it.
I would like to explore the possibilities of this more. Have you any examples of an application using a small centralized blockchain? I am building an application on Python which I would like to incorporate with blockchain somehow. I don't have a clue how to do it at this stage but each day I get a clearer picture.