hell the manual production requirements are pretty much shown to be a non issue in the linked article. making a book shelf is little different from a table and

hell the manual production requirements are pretty much shown to be a non issue in the linked article. making a book shelf is little different from a table and a set of machines could just churn them out. the difference is variety. variety means no single product is a very large seller which can defeat economies of scale. the bookshelf in the article is generic and can be done on the cheap. Other furniture items tend to have more variety