The point is: If I throw a ball to you just out of your reach, you move to catch it based on where you hand needs to be. I would doubt that you would shuffle, twist or contort yourself or think about what your body is doing. See ball- catch ball. I am not discussing chains, sequencing, etc.
My job as an instructor is to help people learn and enjoy the game. If I can do that and help them reduce or avoid injury because some other teacher gave them the impression they need 120 degrees of shoulder turn, then that is what I will do.
Dr. Seaman did his research and it's not my job to prove it is credible because someone else doesn't like it. If you or anyone else wants to take the time and refute his findings then knock yourself out.
__________________ Hitting the Ball is the easiest part of the game-hitting it effectively is the most difficult. Why trust instinct when there is a science."1-G.