I'm no expert at machine learning. However as far as I remember the point of doing cross-validation is to find out whether your model is robust. Robustness is not a standard "Bayesian" concept. Maybe you don't appreciate it's value?
I would appreciate if there was en explanation of why something is done the way it is. Instead it's all about learning the passwords. Maybe it's just that the main textbook in the field is pedagogically bad, it wouldn't be the first time.
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.
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