The inherent misconception of the author is about “seriousness”. His hypothesis is that taking Discworld serious is “good”, while taking LOTR as serious is “bad”.

No, it’s really about taking either universe at face value, which is the problem. And with Discworld, its overt absurdity and humor forces you to think about it more deeply.

LOTR doesn’t make an effort to explain what it is about. But knowing just a little about history and the author goes a long way.