It is repeated because the advancement of civilization has enabled us not to think about the intermediary steps. It's a reminder to sometimes think about the pr

It is repeated because the advancement of civilization has enabled us not to think about the intermediary steps. It's a reminder to sometimes think about the process itself. It can lead to discoveries that can improve the entire process. The 'erroneous truism' is like the saying "Don't judge a book by its cover." The meaning of the saying isn't that you must ignore the cover and judge every book by its content. Picking out a book to read from the library would be impossible. We still need to make decisions based on heuristics. The saying is simply a reminder that sometimes a poor outward appearance can have a gem hidden underneath.