I don't understand why QGC still only supports X-Box controllers.
More accurately, QGC supports XInput controllers (like xbox360 and the logitechs).
The joystick libraries were overhauled at some point last year. Support for HID was probably lost there. I would like to be able to support more methods of input, such as joysticks like this, custom built controllers, and keyboard input. This isn't a priority at the moment, but it will happen.