I highlighted in bold key parts of your statement above. I think they indicate that these issues are all shades of gray - there's no black or white. I'm sure you already know that. When I coach kids, I try to push them towards perfect mechanics. Whose perfect mechanics? For me, it's mostly Tom House's mechanics. But it's also my own mechanics based on what I learn elsewhere including what I learn here in this website. So, although I tend to speak in terms of these ideal, I probably agree with you more than it seems.
That's certainly a possibility. On the other hand, it is common that in order to get a pitcher to make a change, I have to make them over-exagerate it. In this case, it is very likely that making a pitcher keep his head on line with the target 100% will cause him to make a good improvement and, at the same time, he may learn that 100% is really not optimal for him but say 90% is. Ok, he just learned something valuable.
I think you slightly misinterpretted my point. My point wasn't that there are only one or two pitchers who tilt the head. In fact, my point was really the same as your's - that there are pitchers who have gotten good at doing things in a less than optimal manner.
When I coach kids, however, I never tell them that something they're doing sub-optimally is ok because they'll figure out how to adapt. Instead, I steer them towards the most optimal way of doing things (IMHO, of course) until such time that I conclude that what I thought was ideal isn't ideal for them. I think this approach increases their chances for success and health.
Poor choice of words on my part. It's not about right or wrong but what's more or less effective.