The origin of the term is contested, but may be derived from "George Stick", named for a possible inventor.
I knew the device itself predated gaming, but I always assumed it gained the joystick name from some game company. I'm surprised to to learn its unrelated!
Yeah, it's bogus. This is some speculation that someone put in Wikipedia but there's no published source. It's just a folk etymology that some enthusiast thought was endearing. Not a single reputable source will substantiate this, like most folk etymologies.