Well, all the computers I've ever programmed are made of circuits, and I've cobbled together a few hundred circuits in my life. I think it's good to understand the fundamentals of what you're doing rather than write it off as magic, and even though in some ways the von-Neumann-machine abstraction is unmoored from the underlying implementation technology, in other ways it is not.

Also, though, I want to bootstrap programmable autotrophic self-reproducing automata, in order to put an end to the scarcity of capital that is such a limitation on human potential. Those automata need control systems, and despite the obvious fabrication difficulties, solid-state electronic circuits have major speed and reliability advantages over the other alternatives.