Comment Re:PR works well? Where? (Score 5, Insightful) 413
The great virtue of 'first past the post' is that it forces parties to appeal to a wider group than their obvious supporters...
I'm not sure that's necessarily true, but what FPTP does do is push everything towards a two-party state. This is why you get, effectively, extremists on both sides. Case in point: UK and USA. Minor parties are pushed out, moderate viewpoints are ignored. FPTP directly leads to "Us v. Them" contests.
In fact, thinking more about your first point: I don't think it's quite true. FPTP encourages parties to talk negatively about their opponents rather than push their own positive points.