Maybe they had him focus on the wrong things, maybe they instructed him in a technique that didn't work for him, etc, etc. I mean, we absolutely know that Quinn overemphasized things that were detrimental to offensive development.
I am not disagreeing that at some point players are, in fact, mostly finished products, but at age 18 or 19 that is not the time. Those players are still in very moldable formative years for the most part and need good coaching.
You can't just turn 'em loose and say figure it out, you are a professional now.
Come to think of it that may be the Rangers big problem, if apparently so many of their fans think that's the way to handle a kid.
Gustav Rhydal does.