1. Quality over quantity. People SELDOM have this kind of attitude and I love it that you feel this way.
You know I talk about word service a lot. Well "training movements" or "training lifts" is a BIG example of word service. Trainees get so focused on numbers and training the lifts or movements just means getting bigger numbers. Weight, reps, etc…
Every time you turn around you see another article about "breaking through plateaus" and again, it's just doing whatever is necessary to get one more pound. How many times have you seen someone ACTUALLY talk about consciously spending time on improving the quality of a lift? When, the reality is, all this hyper-focus on numbers means quality decreases as our desperation to to hit those numbers increases. Which means, in the end, our ability to hit those numbers hits a lower ceiling than would otherwise have occurred.
Getting stronger out of fear of becoming weak is bad. It's purely negative reinforcement.
3. OH squats versus shrugs: I recognize a thought trap here.
A. OH squats are SIMPLE. There is nothing really technical or difficult about the maneuver itself. It is simply "hard". That is, the symphony of muscular interactions needed are very complex but the conscious act of going through the movement is simple.
So this simple exericise is HARD to learn. It takes a great deal of dedication and you have to be able to deal with some frustration.
By comparison shrugs seem so primal and simple. Much less going on. So you automatically assume that shrugs should be a no-brainer and if your form breaks down it has something to do with brute force that makes your form break down.
The biggest difference is that OH squats by virtue of their nature are unforgiving. You have to do them pretty darn close to correct or you basically end up with technical failure. In this way they are different than many other exercise and certainly different than shrugs.
So what you have here is the dichotomy between an exercise that forces you to do it right and and exercise that you can do any old which way..much to your detriment.
All you need to do is let go of the assumptions and expectations and accept that any movement may need some attention paid to quality.
With shrugs you were letting the weight pull your shoulder forward and then pulling primarily back instead of up. This is very damaging to the shoulders. Incidentally, however, this is a "method" that was touted by many muscle mag types as a way to grow bigger traps.
So that is another aspect of certain exercises that give a lot of wiggle room in performance. They open the door for people coming up with their own 'versions' of the exercise. Those versions float around and become "correct form", usually by nature of how big the guy was who came up with it…whether in reputation or muscle. It becomes difficult to know what is correct without resorting to learning more in-depth biomechanics and kinesiology, etc…which most would rather not have to do.
This is even true with something like the back squats, and we all know that you can do back squats wrong for years and get away with it. Which means that any jerk can get away with selling you any crapola about a back squat because by the time it becomes a problem…the problem cannot be traced to him.
Which is why I love things like overhead squats. There is just not enough room for people to play around with them. Yes, I think it is possible to do them "wrong" but there is a very finite cutoff in terms of load where wrong becomes failure. Not so with back squats and all sorts of other things. You can do a goodmorning, call it a back squat, and be none the wiser until someone points it out to you.