Well, WW1 really is the pointless war. If anything, it distracted the European powers from Asia and gave Japan an opportunity to finish its occupation of various parts of SE Asia and build up their fleets for their eventual attack on the Americans.
The reason why Canadians "care", and even then I don't think the average Canadian knows any Canadian history, to be honest, is that WW1 defined Canada as a nation, both internally and to the world, or at least the British. Passchendaele is one of those "big battles" like the Battle of the Bulge which sort of define the mettle of a nation's military and victories in WW1 helped cement Canada's role as a contributing world power.
Internally, of course, it basically fractured Canada much more than anything else - the draft was vehemently despised in Quebec since they did not feel any obligation to a British led war. If anything, WW1 set into motion the notions of the separatist movement.
Still, I dunno. Maybe I'm just misinformed, but I just can't get worked out about WW1. It basically signalled the transition from old outdated European powers to the new powers like the United States, and it featured the development of a lot of military technology... still, there's no big mythology built around it the same way there is around WW2 or Vietnam.