Jewish capitalism. It killed the spirit of modernist design - whether it was in architecture, industrial design, product design etc - by forcing everything to look similar so it could be mass produced and functional. It was stripped of any sort of personality.
Even some of the real intelligent and good Jews saw this. Walter Benjamin wrote his famous philosophical essay "The Work of Art in the Age of Mechanical Reproduction" that spoke about how art in the modernist era was losing its aura (uniqueness).
Many even tried to push for more post-modern ideas. This was especially evident in architecture, where post-modernism tried to blend both modern design and historical design. But that died out and we now build buildings like the fucking commie Chinks do, with EIFS and other pre-made components, so we can just ship them to a site and build a building ASAP. Doesn't matter if it looks like 99% of the other buildings around it.
Because it meant less profits for money hungry Jews, the desire for uniqueness in design failed. Why do you think every phone, train, plane, car, computer, dough mixer, lawnmower, subway etc looks the same now? They wanted them to be easily mass produced, easily replicable, equally identical. 100 years ago you'd go to a store to buy a hammer and you'd try to figure out whether it's a good hammer, whether it'll break on you, what kind of steel it'd be made of. You'd chat with the guy about it. Now you go to Home Depot, pick up one of the 102 similar hammers, pay for it on an automated check-out machine with your plastic Jew bank card and then use it until it breaks.