Because, unlike even tin-pot dictatorships like the UAE, we've decided to allow provinces to control their natural resources and act stupidly with them on their own.
Otherwise, we could take what Alberta, Newfoundland, soon Saskatchewan are doing with oil and add to it what BC, Ontario, etc. should be doing with timber, and Quebec, Ontario, BC, Alberta, could be doing with nuclear power and actually, you know, have money flowing to our advantage the way the Chinese, UAE, Singapore, even Russia are starting to see from the run-up in raw materials.
Why have a national debt when you could build up a fund instead? Great post, great question, sad answer ... provincial governments have been the bane of Canada's existence in EVERY part of the country (Quebec, Alberta, even Ontario, etc) ... but try changing the Constitution anytime soon ...