I'm pretty sure the Poutine in McDonald is exclusive to Québec or perhaps it's also in some select places close to Québec, like everything McDonald serve, it's awful. Well, in Québec Poutine is so popular that even Chinese restaurant have Poutine in their menu.

Burger King also serve a really similar bas tasting poutine.

I also remember that McDonald used to sell Pizza in Québec (don't know about the rest of Canada) and as I heard (which is not surprising at all), it was awful too.