Further more, engineering is more than just bolting bits of technology together - you cannot tell me you think taking a protocol designed to run over a wire and whipping out the phys and then emulating it over the a UWB is a good idea? What happens if you move your laptop out of range (by accident) while you’re writing data to your USB mass storage device connected by a WUSB bridge - as mass storage is SCSI level commands you better hope it wasn’t updating the FAT when the link got kicked out from underneath it. Unlike with a wire where you know you’re doing something wrong (tugging at the cable), with wireless you don’t have that strong a guarantee, you have to expect that the connection may just drop due to signal strength or interference.

Finally, Bluetooth is going to be better for a lot of the use cases WUSB has. For example, mice and keyboard - the advantage USB has is that they can be powered. With WUSB you lose that power cable and so need batteries or a power supply (and so are on the same footing as Bluetooth). Now for WUSB you are mandated to use a UWB radio! You don’t need UWB bandwidth for HID type traffic, all it serves is to drain much more power. With Bluetooth you can use the standard Bluetooth radio in an appropriate sniff mode, which is perfect for HID traffic (and much much lower power than driving UWB).
And Bluetooth will be getting UWB too - in addition to its the standard radio - so you get the benefit of high bandwidth for profiles that can benefit from it, but also the low power consumption for devices where there is little bulk traffic transmitted.

In my opinion, USB should stand for Unrivaled Shortsighted Bodges, I mean one only has to look at OTG! And slapping a UWB radio into the mix just makes things even more messy. It seems to me these days that time-to-market and well-it-works attitudes prevail. What ever happened to well thought out and finely crafted architecture?