The USB protocol looks to be a whole mass of complexity. So if you want to write your own toy OS then you're going to hate the very existence of USB.
And what is actually broken about PS/2 keyboards/mice anyway? I only ever want to plug in one keyboard at a time. Being able to plug it into any slot doesn't really buy me anything that a dedicated slot doesn't.
The trend in computing is to make things more complicated, not less. We keep shovelling the spaghetti on. We just can't help ourselves.
In the early days they just wanted things to work. Sure, I don't necessarily want brutal simplicity with a lot of jagged, flesh-tearing edges. But, then again, I don't want the big steaming pile of complexity with dubious payoffs.
I have some vain wish that maybe RISC-V will take off in a big way, and some clever operator will come out with a computer that takes 80's simplicity and moves it into the 21st century. In fact, I'd hope for something simpler, yet more powerful.
I also imagine if you decoded how much of the USB protocol is needed to operate say a USB-to-PS/2 adapter and keyboard, that would be much smaller than the spec. Don't need power delivery or video or higher operating speeds? Things get much simpler.
