Wow! I never thought about it in that way before, but it does make sense. A woman couldn't propose marriage, and she couldn't change her mind after the wedding, so this is really her only window of power. And with the possibility of a Breach of Promise suit added to the fact that everyone rightly thought you were a cad, no wonder a gentleman had to take it seriously.

Thanks to everyone for your thought-provoking comments! I love the stuff you can learn here.