"While France, Germany, and other countries got their early PC with customized keyboards whose layouts mirrored closely the typewriters that came before… [...] …in Poland, we had to find another way of inputting the extra 9 diacritics unique to our language." Did we? I dare to say that your historical account is inaccurate. We stuck to our traditional layout for a while. What does it matter if the keyboard wasn't cus…
It's way worse: it's installed by default up to (at least) Windows 7, along with a silent (no feedback!) Left Alt-Shift shortcut that switches the keyboard layout. Press it unknowingly and BAM - suddenly your diacritics don't work anymore and Y/Z are swapped. Annoys the hell out of an Average User.
PS. I'm not saying that the layout was bad - just that there shouldn't be a magic shortcut for a "break my keyboard now!" feature.