I always wonder if John Dashwood were fond of his wife because she was pretty (the text is silent on this point, but she is so unlikable that film makers tend to cast her as pinch-faced, or shrewish-looking), or because she could flatter and maneuver him into doing what his baser instincts wanted to do anyway.

Author Austen tends to make the best couples bring out the best in each other, and the worst ones bring out the worst in each other. I think the John Dashwoods bring out the worst in each other.