However, it seems the author was discussing a different meaning of "lost", as in loss of control of the source and having it revealed to the outside world. He made the best arguments I've seen that the bulk of it is worthless to anyone else, who would be better off rolling their own from scratch, and provided a good example.

Indeed, if I were working a problem and somehow ethically came into possession of a competitor's code or product (e.g., via a buyout), the only use I'd put it to would be to try to see if they had any unique insights that we could adapt, and maybe some stand-alone chunks to use. And, indeed, that was the fate of a codebase of which I was quite proud when a company I co-founded got bought.

The saleable product has value. A library you use for multiple products has some value. Everything else is cost.

Therefore I conclude that engineers have no value for a company, since when ignoring all the value they provide they just cost money.