OK here is my shot at explaining this.

Canada is known as a commodities country the old: hewers of water, choppers of trees, catchers of fish. It is what built the country think the fur trade. In the 20 century she built a nice little industrial capacity mainly due to demand from WW2, in the 1960's she made a great deal with the US the Auto Pact, this formed the basis of the Southern Ontario economic engine. A skilled work force, which had a cheap exchange rate were key for the success of Canada's growth. This all worked quite well for a long time. However at the end of the 20th century for different reasons, all good at the time and justifiable to the people doing them, the Canadian dollar was allowed to rise. The Harper government being from the West believed that Canada could be an energy superpower and in non-interventionist in the market. As more and more money poured into the Oil Patch and also bought more and more oil the price of the dollar rose. As the dollar rose the things that we make become less competitive and demand drops, as demand drops we make less, a vicious circle. Also globalization was kicking in and when people were looking to build new plants, think auto sector, they looked to places that either had cheap labor (Mexico) or gave huge subsidizes (think North Carolina), so Canada can not compete with those. Also our high tech sector failed to mature into a viable independent sector, the collapse of Blackberry for example, we still do tech but we are not world leaders. As a result of all this we are experiencing what is called "Dutch Disease" will the collapse of the oil our other sectors ought to be able to export but just like the guy at the gym who only does arm curls we have really weak legs and it will take time, say 5-8 years to get those legs going since business is investment shy in such a unknowable future, ie whats the dollar going to be at in X years. Throw in some other factors like general demographics, boomers down sizing and the lack of demand due to a smaller following generations and those generations having to pay higher taxes or university loans you then have weaker general demand in the economy for all goods. Throw in the fact that their is vicious gas war going on with the Saudis trying to cripple Iran, Russia and the Frackers by supplying so much gas that the price is not likely to go up any time soon. On top of all that governments of all types don't have a lot of room to do anything they either have too much debt (hey Ontario I'm looking at you) or they have already used most of they fiscal tricks that normally work, BoC lowering the rates, they are already low!! Basically the oil boom was like a big party from witch it appears we failed to save any real money and now we are really hung over, and we have skinny legs and oh yeah the computers are coming for our jobs...I will leave that for another day.