Logically "love marriages" make plenty of sense but the data proves (in the US at least) that it doesn't work. At least not once the human factor is taken into account.
People from cultures where arranged marriage is not acceptable seem to have a very hostile view on it. There's good and bad but having come from that culture as I grew older I began to see the benefits.
No, it doesn't. To actually prove love marriages do not make sense, every single love marriage should fail. Anyway, 50% is a pretty damn good success rate, I think. I don't think I could choose someone to spend the rest of my life with correctly on my first time. It's perfectly natural to fall out of love - that doesn't mean that love marriages don't work, it just means that some don't work.