That being said, there are also programmer's layouts specific to single languages which among others have a semi-colon on the home row.

I've never seen QWERTZ keyboard in Poland and I live there. Typewriters indeed were using this layout, but not many people use them to program.

"practically all computers (except custom-made, e.g., in public sector and some Apple computers) use standard US layout (commonly called Polish programmers layout, in Polish: polski programisty) with Polish letters accessed through AltGr (AltGr-Z giving “Ż” and AltGr-X giving “Ź”)." http://keyboard-layout.info/#Polish

There's no need to use shift to get a semicolon on a french keyboard.