Reading the article, it seems more about programming your sketches to react as you draw, than using sketches for programming. I think both directions are interesting, but actually the latter catches my imagination more.

Visual scripting could be a good start. Unreal's Blueprints are really good with their UI and they provide plenty of usability. Perhaps if you could draw your own nodes with the properties you want, this could create the missing link for a truly hand drawn visual programming language.