USB was a BIG deal, and a big improvement. It wasn’t the keyboards, it was the printers, scanners, external hard drives, and Zip drives.
Macs had something called “plug and play.” You plugged in a peripheral and it Just Worked. PCs didn’t have that. USB was intended to be the solution, and the most part, it succeeded.
BUT… the PS/2 connector was also a problem. In addition to there only being one keyboard connector on a typical computer—that happened to look just like the mouse connector, and wouldn’t work if you used the wrong one—it had an electrical flaw that could actually damage your motherboard if you plugged/unplugged it while the computer was on.
So, yeah, maybe don’t hate so easily.
And the connectors themselves have been great. Aside from PS/2 connectors, most other things use some variation of a DB9 connector. Mechanically, you could plug all kinds of things together that were not electrically compatible.
I seem to recall that there was some proverb about systems becoming so baroque that they eventually become rubble.
It seems that USB is sewing the seeds of its own destruction. No doubt that within 20 years they'll decide the whole thing is so complex that they need to replace it with something simpler.
And I'm still puzzled as to why plugging a keyboard into a keyboard port was considered such an inconvenience in the first place.
I think that USB is an object lesson in why you can't reduce inherent complexity, only shuffle it around.