> DO NOT JUST PASS THE SECOND BALL BETWEEN YOUR HANDS. This is a common thing, as people are regularly taught it
People are really regularly taught it? Who's doing that teaching?
I suspect a different cause: cartoons. Especially in older animation, juggling was typically presented in the 'circle' style, which is probably where people tended to pick up the misconception. I guess that animation is a lot easier to produce.
In my experience they're not taught it, it's instinctive. The easiest way to get a free hand seems to be to hand a ball over to your other hand directly. It makes sense too, it's counterintuitive that it's much easier to throw the ball up and over back.
I grew up in the boonies back in the 80's. The only real contact I had with juggling was probably cartoons like described above. I really wanted to learn though and would walk around the woods for hours trying to juggle oak galls in that "circle style" only able to keep it up for a few seconds at a time.
My first day at college, before classes started, I was in the dorms. Everyone was getting to know each other, and I saw someone juggling the right way. It instantly clicked. All the hand-eye practice the 'wrong' way actually helped. That's why I always tell people that the first thing I learned in college was how to juggle.