Probably not the code, though it's true that everyone starts with the toaster sample, there's not enough functionality in it to make it an easy walk to a HID filter driver, which is what's probably installed for your average white box USB keyboard. Plus there's (IIRC, it's been a couple of years) a specific sample for that in the WDK. Most likely they did copy/paste the device metadata from that sample.

So, keyboard OEM's contract devs whip up a HID filter driver, but they c/p the sample metadata and forget to change the DeviceIcon entry. Now we could imagine their testing process involved little more than jacking it in and rattling the keys, but if they were developing or testing on anything previous to Win 7 (I think) then if they'd checked they'd have seen a generic icon based on device class.

But still, the code they wrote is running in the ring zero, so yeah, we'd prefer them to systematically carefull.