Blame Bauhaus and the Braun company!
“Neither Jobs nor Ive tells us exactly what he means by “pure,” and Isaacson is not much help here. It appears that “pure” products exhibit a perfect correspondence between their form and what both Jobs and Ive refer to as their “essence.” Ive notes that “we don’t like to think of our knives as being glued together. Steve and I care about things like that, which ruin the purity and detract from the essence of something like a utensil, and we think alike about how products should be made to look pure and seamless.” It is a kind of industrial Platonism. All knives have an essence, and if the form of a given knife corresponds to that essence, then the knife, the designed object, is perfect, or pure. Nothing compound or cobbled together; only the integrity of a single substance in a simple form. Pure products are born, not made; any visible signs of human assembly—say, screws—would make it hard to believe in the higher integrity, the perfection, of the product.”