Maybe only 1 in 10,000 crackpot ideas
As we all know, crackpot ideas only work if they are a one in a million chance, and throwing a few million pounds at each one would cost several trillion pounds to get one to work. Therefore, all the effort should be devoted to the (almost) infinitely improbable drive. Once we get to an improbability of one million to one, cold fusion and reactionless drives will just start popping into reality all over the place.
Biting the hand that feeds IT
