Exactly. I have a colleague who worked on some part of the control software of the Space Shuttle code in the 70s and he tells me that at some point, NASA's man

Exactly. I have a colleague who worked on some part of the control software of the Space Shuttle code in the 70s and he tells me that at some point, NASA's management decided to freeze the source code so no more modifications to it were permitted (sensible, if it's done) but they still wanted to be able to change the behavior of the software. The inevitable result was that someone wrote their own DSL for patching the object files generated by the original source code directly.