I interpreted it precisely the opposite. PC mobos were like "Look, you can use the new things if you have any, but we're not gonna make you throw out your PS/2 peripherals that you know and love, or even buy adapters for them, because all that stuff, and the support circuitry for it on the mobo, all works just fine."
The all-in approach required a forklift upgrade and generated a ton of e-waste.
> The all-in approach required a forklift upgrade and generated a ton of e-waste.
It really wasn't that bad. I lived through it.
The iMac was pitched as an entry-level Internet computer for new computer users. Many buyers didn't have a computer at all previous to purchasing an iMac, or only had one which was old enough that its accessories would have been irrelevant (e.g. an external modem). Probably the most common USB accessory purchase was external floppy drives - and a lot of users ended up discarding those after they realized they weren't using them.
The all-in approach required a forklift upgrade and generated a ton of e-waste.