Weight is an issue that MUST concern a coach. It has an impact on performance and if managed, can therefore improve performance.
The issue is that to discuss this FACT, a coach touches the third rail - the untouchable! I am not defending belittling / shaming of athletes, but if a coach cannot even discuss the topic of body composition / weight, then it is like they are fighting with one hand tied behind their back. There must be a sensible way to discuss this with athletes without touching the third rail and electrocuting oneself.
My own D1 female running daughter just went to college and promptly put on 20lbs. She brought it up on the phone, knowing it was a massive problem for her performance. We discussed it and tried to ferret out the problem(s). We did not put pressure on her, but talked dispassionately about the fact that every pound put on was extremely difficult to take off. It was helpful for us to read Stacy Simms book Roar that discusses the impact of women's menstrual cycle, of birth control pills, and of food/supplements on engery levels, weight, and performance. We are managing the weight and have corrected the problem, all with no input either way from her coaches.
If the accounts are accurate, Salazar and team handled the topic horribly. But pro-level and collegiate coaches must be able to discuss and help manage, though not shame or blame, athletes weight. Good luck coaches, because doing so is like walking through a mine field.
Lastly, NOP is at full fault for its actions regarding Cain's handling. But if that happened to my kid, I would be beside myself with guilt for not vetting the program better and/or not monitoring what my daughter was going through. That it happened once was not my fault. But that it continued to happen, yes, that is at least a bit on me as a parent.