Language is everything and essential to negotiating meaning, and yes, people are passionate about such things; isn't what this forum is supposed to be about?
I find it interesting that certain cities "marketing" of transit becomes a defining attribute of the city itself: the Chicago "L", the London "Tube", the Seattle "Monorail" as opposed to Vancouvers "Skytrain, the "T" in Boston to name a few. It is a shame that the Paris "Metro" has now become a generic term like "Kleenex".
Perhaps we should embrace the "REM" as a marketing tool for Montreal transit - when you Google it, the only thing that comes up is the Montreal system (besides "Rapid Eye Movement", and of course the band of the same name).