I think the software as language/literacy metaphor is taken too far. A lot of this is because Chomsky was such an influential thinker, and people take it too far.
There's a lot of language in formal math and science that isn't talked about in a way that assumes everyone will learn it. If you don't know how to code you aren't illiterate.
My take is software is a new form of literacy- not some neat technology like lasers or combustion engines. It's about human knowledge and human co-orindation - and we will all have to code just as we all have to be literate.
As such how many human systems today have not been fitted and overtaken completely by the written word? Some maybe but precious few