It seems as if you got the impression that the linked material was meant to be some sort of argument for my view; it was not. I only linked it because it contained some related, and relevant, ideas. (Though your aside about unspecified “nonmaterial” things being “blatantly obvious” intrigues me. Perhaps you might elaborate on what you refer to? Though of course this is tangential to the current topic.)
In any case, I am not sure what to do with the claim that “[y]ou must find something meaningful to have a purpose”. Is the sense of the word ‘meaning’ (or ‘meaningful’) here the same one as in claims like “People crave meaning”? Or is it a different usage? I can’t see any way to interpret this claim that would make it both true and non-vacuous. Perhaps I am not understanding what you’ve got in mind.