I'm afraid I'm not familiar with the particular customs you refer to - I'm not a medievalist. As someone who is more of a folklorist than historian though, I can perhaps lend some insight into the academic study of folk beliefs and customs such as these. Your question essentially is based in the Functionalist school of thought, originating with Bronisław Malinowski, which very broadly assumes that culture serves a function for individuals.

In his 1954 article Four Functions of Folklore in the Journal of American Folklore, American folklorist William Bascom argues for four basic functions of folklore (within which folk beliefs and practices would fall):

• As a teaching tool for ethical, practical or moral learning.

• Creating a system of social control to prevent antisocial behavior.

• Validating the purpose and correctness of culture itself.

• And as form of escapism to relieve social tension.

So your own question challenges the last of the four. And... well you are probably correct to be dubious of such an tidy explanation. Now it could be this is a well-known and rigorously established theory for these particular practices, but it does have the scent of popular interpretation to it. The reality is culture is unbelievably complex, and the more you try to press it into small boxes, the more it slips away from you. My suspicion is that a historian studying the period and events might argue that something like Bascom's functions might have played a role in the broadest terms, but there would be infinite number of other contributing elements.

I'm sorry I'm not able to provide and answer, but hopefully this serves to at least validate the astuteness of the question.