Comment by youknownothing

"We treated code as permanent because the labor to produce it was the bottleneck."

I don't think that's true. We treated code as permanent because we considered code to be the source of truth. Computers don't run documents, computers run code. If the requirements document contradicted the code, then the default was to assume that the requirements document was wrong.

You can't separate code from spec because the code is the spec.