The security implications if this goes mainstream is that you are expected to do this for all kinds of hardware.
Right now that isn't the case and I can't remember last the time I had to uninstall untrustworthy native drivers.
A lot to lose, very little to gain?
So what is an example use case where you'd prefer to do X without using this particular tech?
I felt that way too, but having used it a few devices as an end user I enjoy being able to close the browser and have the whole stack disappear. Instead of having to install a creepy Logitech tool to pair a mouse with a receiver, as soon as that task is done, goodbye Logitech. I guess a real concern is manufacturers stop offering native drivers, but for the majority of hardware the PnP or the Linux kernel just handle it.