This is because all the oil sands production can be routed to the west coast for shipment to Asia or anywhere, thus avoiding monopoly pricing and bullying by the Americans.
Besides that advantage, oil sands are the national trump card in the future and the American economy, now sputtering, will never be as robust as before.

I'm afraid that the Americans have first dibs,thanks to PM Brian Mulrooney having signed Canada to commiting 80% of Oil production to USA as I have said before God help us if Canadians should need more than 20% of its own production.This agreement was signed so as to acquire the infrastructure monies neede in the Oil Patch,seems Canadian investors were no shows,I suppose the reasoning being its better to have 20% of something than 100% of nothing,???