Fairness to voters is normally understood by everybody as a share of the votes going to a share of the seats. So any system that is majoritarian systematically penalizes the parties that are in third, fourth and fifth place, and always gives a winner's bonus, an exaggerated bonus, to the party in first place, whoever that party is.
The majoritarian system is not designed to have fairness per se in that regard, at the heart of it. It's designed to produce a strong majority, to get decisive decisions with a strong executive. That can be a fundamental problem because over the years, particularly since the 1950s, there's been a dealignment, progressively, in nearly every country in the western world and a proliferation of many more parties because people aren't necessarily seeing themselves in class terms as supporting the parties on the left and right. They have many other interests, like the environment—and also, it has to be said, like populous parties on the right. Party systems are fragmented and first past the post majoritarian systems try to squeeze what the voters actually want to do in terms of their party preferences into a system that doesn't allow that sort of representation. That's really a very strong argument to say that some sort of reform in Canada is very appropriate.
Majoritarian systems work proportionally if you're a two-party system. If you're in the United States and you can only vote Democrat or Republican—by and large the libertarians and the Greens are going to get, at most, 5% of the vote—then you get a roughly proportional share of votes to seats. If you get five parties, if you get 10 parties, if you get 15 parties, as increasingly most countries are having, then even though they get a share of the votes, they don't get full representation, so a large part of the population is not represented through the electoral system. It's the classic argument in favour of some sort of reform. It also will affect, on my projections, the NDP. It won't affect the Bloc Québécois so much, because they're concentrated in particular areas. But the Greens, who are spread across different parts of Canada, will always lose out from the current Canadian system.