On paper at least, it makes sense. Representation in legislatures here doesn’t depend on how many votes a party gets, but rather how many it gets in 125 (or 308) small areas. This system of democracy encourages local and regional parties with local interest, such as the Bloc and the Reform parties. These smaller regional parties eventually die out usually by getting absorbed into larger parties, or losing the media campaign wars to a larger all-region party.
But for over a decade in Quebec, anglophone federalists have learned that you either vote Liberal, or you vote separatist. So long as that mindset exists, there will always be two front-runners and the seats in Montreal will only be won by one of the two parties.
Then again, what do I know? The last federal election sent Quebec Tories to Ottawa, something I would never have predicted.