One of the best things about this place!

There are advantages and disadvantages with a system having more than two effective parties - as you point out, Robert, it tends to reduce polarization, and it can give other viewpoints a voice. But it can lead to a minority government, which can in itself be a good thing in many ways (more accountable and less extreme), but which tend to be short-lived and feeble, leading to more frequent elections, which are annoying and expensive and also make it hard for any one government to accomplish anything significant.

Electing the government by via first-past-the-post representatives also means that smaller parties, who may have a significant percentage of the popular vote, end up not having any elected members of parliament. The Green Party in Canada got 4.5% of the popular vote in the recent election, but no members... the separatist Bloc Quebecois, running candidates only in Quebec, got 10.5% of the overall vote, yet they have 51 seats in parliament (out of 308).