Why JRR Tolkien said that he cordially disliked Allegory

Over at my Notion Club Papers blog, I describe that Tolkien did not so much dislike allegory as such; but allegory when the term was falsely applied to his mythopoeic works such as (especially) The Lord of the Rings. 

I discuss that allegory pushes the reader or viewer out of its story-world, and back into the ordinary, mundane, materialistic world. What happens in an allegorical fantasy is thereby, intentionally, mapped onto everyday experiences.  

Whereas Tolkien's fantasy stories underpin their imaginary worlds with depths and enchantments above and beyond our everyday experiences. 

I further point out that the degradation of modern fantasy worlds (such as Doctor Who, Star Trek and Star Wars) often operates by transforming them into allegories (under the term "relevance") - such that their characters and narratives are reduced to token representations of current issues and news stories. 

By imposing allegory on an imaginary world, a fantastic story ceases to be profound or magical, and becomes merely topical.