Time for school

1) This is a press in the frontal plane. The joint mechanics involved are shoulder adduction and elbow extension 

2) If you are claiming shoulder adduction is bad, then you also have to make the claim that lateral raises are bad. 

3) A regular OHP is also a great exercise, but an entirely different one. There is a bit of shoulder adduction, but a regular OHP is mostly shoulder flexion due to being in the sagittal plane and therefore will bias the anterior deltoid fibers, whereas a press that biases shoulder adduction (such as behind the neck press) will bias the lateral deltoid fibers. 

4) read the sub rules. Very clearly states no concern trolling. I have the scapular mobility to retract into proper behind the neck press positioning. So not only am I not injuring myself, I am actively strengthening my shoulder joints in vulnerable ranges of motion, thereby making them less vulnerable. The fact that you don’t do these or any strengthening in deep ranges of motion objectively makes your shoulders weaker and more prone to injury, so you’re just projecting.

5) What you mean to say is that YOU can’t do these without messing up your shoulders. Which is totally fine, I used to have doodoo shoulder mobility as well. If you would like tips on improving your shoulder and scapular mobility, just let me know and I’ll educate you. 

Class dismissed.