There has been a huge awakening about swing mechanics in the last few years. Thankfully, some prominent instructors stepped up and got beyond "see the ball, hit the ball", and actually started TEACHING HOW to properly "see the ball, hit the ball". Because of the in-depth study of swing mechanics, we soon came to realize that throwing and hitting mechanics are very closely related.
The question is: Why do most boys generally know how to throw a rock, and girls, for lack of a better phrase, "throw like girls"? When I was a kid, I don't ever remember anyone teaching how to do a basic overhand throw. Yet, nearly every boy just picked it up on their own. There were exceptions - I grew up in the neighborhood with the late Muskingum softball coach Donna Newberry (and her cousins). Donna could throw a football better than most of the boys. I wish I would have asked her how she learned that when I had the chance.
Extremist, you are right on track, and exactly right! Just as with anything in the teaching/learning process, some will learn, some won't. Some students work hard and SMART at it, some do not. For instructors, the most frustrating thing is students who refuse to practice on their own. It would be great if every student was an eager beaver, but that's not realistic. You just have to do your best with the ones that are there to soak it all up.
I remember when my daughter was learning pitching, there were phases where she regressed - off balance, timing problems - you name it. Fortunately, she had instructors who had the mindset of "going back to square one". Two steps forward, one step back. You cannot move forward until you get the foundation correct. Boring for kids? Not if you're creative.
Top athletes "go back to square one" before every game. Warm-ups should include precisely executed throwing progressions. If not done correctly, it only reinforces bad habits.
The elephant in the room is why are boys "easier to teach" throwing and hitting than a lot of girls? Thankfully, there is progress being made on that topic. It centers around the fact that "girls are not boys" (duh) - their bodies are built differently (double duh!), and therefore work differently in some aspects. A solid knowledge of those differences goes a long way in knowing HOW to teach girls how to throw - AND hit. So, the challenge is getting coaches on board understanding those differences, and adjust their teaching methods to better suit girls.
very technical. I'm ok with that. Translating "that" into "ah hah"moments for the players is where being a coach comes in. 
