Interesting essay from an informational perspective...but frankly, in terms of what you find enjoyable in literature as demonstrated by said essay, I think you should step far away from the fiction section and remain within the safe, comforting confines of Dewey's decimals.
If 'spirituality' is a catch-all dumpster for 'a common explanation toward things I cannot show empirically at this very moment,' then the criticism is correct: this is a useless discarding of knowledge.
On the other hand, if you don't start with an assumption of first principles, you have no science at your disposal. Certainly, new knowledge can build upon established knowledge; but what did that knowledge build upon? Sooner or later, we must come up with a blank. No question can be asked, and tested, unless it starts with something to build upon. The ...
Of course, Galileo was trying to understand how things worked. He wasn't trying to write escapist fiction.