The last Labour UK government introduced the ban on dual candidacy to avoid a situation where candidates could be overwhelmingly defeated in a constituency but get elected via the regional list top-up system, which compensates parties that fail to win first-past-the-post seats.
The guys at the top are not going to give up control of post-season college football just because a few extra bucks could be made with a playoff system.
But John Maynard Keynes's plans for the post-1945 monetary system were aimed at limiting the imbalances that arose in the interwar system, and have popped up again in the past 20 years.