[whyoh]

>basically everything has usb C on the device end

Yes, but we're talking about the ports on the Steam Machine, so the host end is what matters. And gaming peripherals are likely even more skewed towards USB A, because Macs are not the main target for that.

[Gigachad]

If it has USB-C on one end then you can use a C to C cable or a C to A so it doesn't really matter. It's not a show stopper either way but I've long wanted to slim down my birds nest of cables. Since my laptop and phone are USB-C I can get by with C to C cables only so I probably wouldn't get a computer that required me to double the number of cables I have to keep.