The author complains about not having local variables, but most decent Forth environments have them. It is not difficult to have local variables in Forth, just use a library or compiler that provides them.
http://www.cs.uni.edu/~wallingf/blog/archives/monthly/2017-1...
FYI Moore also designed processors; one of his designs was apparently viable enough to be part of the Rosetta mission. At some point he wrote his own CAD program to design his processors, which are at the very least functional.
It's not "simplicity of implementation" for the sake of it. It's about finding the simplest solution to a problem. But people too often confuse "simple" with "easy" if not "lazy" or "simplistic" - like your depiction of his approach.