While USB is the less crap thing we have nowadays, I have always thought that USB sucks in general, and should have been replaced by a better standard long ago. There are too many different physical connectors (often unnecessarily so - in particular, I've never seen a sound reason for type B plugs to exist), all types of connectors are too flimsy and fragile and become error-prone with time, and power delivery across all USB types and revisions is too low which often is quickly compounded by connectors and cables degrading with time. These issues have significantly improved starting with USB 3.0 (USB 1.x was awful and 2.0 was terrible - USB 3.x is just mildly bad, so that's a big improvement) but are still far from ideal.
At least PS/2 and DB9 serial connectors and cables were a lot sturdier and more reliable than USB (parallel and SCSI not so much but still...)
I do think most of the criticisms on the original iMac at the time of its release were fair and justified. The lack of a 3.5 inch floppy drive or CD writer at a time when USB flash drives and external USB floppy drives didn't even exist yet, and the internet wasn't yet as ubiquitous, meant an original iMac G3 in 1998 was basically a doorstop only useful for content consumption in form of multimedia CD-ROMs or internet browsing, unless it was hooked to a corporate LAN. It was only successful thanks to Steve Jobs' reality distortion field.
