Obviously a lot of you are the same, only the other way around.
Yes, habit is the main issue here.
In my case, I live in Canada, and not in Quebec. Thus, where I live, we only speak English, and we use the U.S. keyboard layout (as opposed to even using the U.K. English keyboard layout, which also has the extra key).
But in 1981, when the IBM PC came out, I had already been touch-typing for ten years on typewriters, keypunch machines, and computer terminals. None of them had an extra key between Z and the left-hand shift. (There were such keyboards
in existence, for example on the IBM 3278 terminal, but they were rare.)
Only on computer terminals did I have to deal with cases where the backspace and Enter/carriage return keys were out of reach (of course, on a manual typewriter, one had to lift one's left hand off the keyboard to push the lever...) so I welcomed the U.S. 101-key layout when it arrived. The 84-key AT layout may have been an improvement, but the 101-key U.S. layout was, to my mind, simply when they got it
right.
For people in Europe who are content with their standard keyboard arrangement, there is no problem, but I am surprised, since alternatives to the standard 101-key layout are common here, that I can't seem to see cases where the 102-key layout has been modified to put the extra key somewhere less obtrusive.