[gpvos]

This hasn't been true since IBM keyboards became popular. For example, on older keyboards shift+number would simply toggle a bit, so shift+2 would be a double quote, etc., but this hasn't been common for decades now. Unfortunately.

[chinpokomon]

Probably on the path to scan codes. By using scan codes, they could abstract what a particular key meant and thereby remap the keys so that they didn't have to match the ASCII table layout. I still don't understand why we evolved scan codes the way we did. This requires the OS to be in sync to be able to map them back.