> the factory line both costs and produces all the value.

I think the point OP is trying to make is that manufacturing and design are seperate steps with different workflows and expectations. And that the design step does have value, as without it your factory line has nothing particular to make or sell.

Nobody is sitting around Ford trying to make the clay modeling step faster or more error free, it's a design function. But there are hundreds of software execs out there trying to do exactly that. In part because cp and git and make and your other build tools that make up the factory line function are pretty much rock solid and cost optimized to nearly free.