My use cases:

* Replacement controller for my UFO Catcher - It has WiFi, easy to update, and I can operate the machine remotely with it. It's bolted to the back of small touchscreen that lets me change the machine settings as well.

* Remote printer access - I can monitor from the USB cameras and gather statistics about the prints.(I suspect a lot of 3D printing enthusiasts use them for this purpose.)

Having a small low power computer has been useful for me in those instances.