"Just curious why the name Alcan is such a sore spot?"
I'll leave it to Sue and Murray to say if it actually is a "sore spot".
My 1st trip was 70 or 72, I think 72. Several (!) trips in the next 26+ years, not many recently.
That first trip, I was too bull-headed to care/notice, but later on when asking/talking about the road when in Canada, I'd refer either to the number designation or "Alaska Highway".....since the "Alcan" reference either drew honestly puzzled looks or "umm, it's actually the Alaska Highway" statements.