Indeed. Newton was a devout alchemist/occultist who believed he could find the temple of Solomon - but it doesn't make gravitation or his laws of motion irrelevant.
It is, however, absolutely essential to take into account the person behind a product when evaluating a product. You would never write an essay on the film stylings of Stanley Kubrick or Roman Polanski without fully considering their backgrounds and personality quirks. You would certainly never write about a work of classic literature without first taking into account the context of when the book was written, what life experiences the author had, or what inspired the author to write such a book.
Products like TempleOS should be treated the same.