It’s the economics of it all. Industrial design costs a lot of money. Money requires margins. There is little margin to be had in building PCs after Intel/AMD, Nvidia, Realtek, etc all take their cut. And let’s not forget Microsoft getting their pound of flesh for Windows. The modern PC is simply packaging.

The flashy gaming PCs with cheap LED lights and backlit keyboards have allowed the manufacturers to increase their margin enough to stay in business, but not enough to fund the kind of industrial design that Apple puts forward.