For me, I think that the answer to the 'why' of the the article's title revolves around trust: even with behavior that is superficially outside of social norms, I have never tolerated anything that I did not feel, based on a long-standing relationship, was ultimately in my best interests. Honestly, I wouldn't want to train in a context where a coach or sensei felt like they couldn't occasionally break social boundaries in order to make important points.
I feel the need to point out that college sports and dojos are two very different situations. While a dojo may have impressionable young adults who don't have the life experience to know the difference between hard motivation and abuse, those young adults are still free to leave. I would argue that college athletes are not. Most, if not all, of them are on scholarships that are dependent on their continued participation in sports. If you walk away from a coach and quit the team, you have also chosen to quit school. If the choice is, deal with it or lose any chance at a college degree, I would say that most students are dealing with it. The coaches also know this, and they get paid based on their winning record. The culture in America is that you must win at all costs, and to that effect, the coaches feel free to abuse their captive players if there is a chance it will get them to play harder, and the universities ignore abuse in coaches that have winning records.
The situation of abuse in a dojo is a bit different. I've personally never experienced it, as any dojo I have visited that made me uncomfortable, I have immediately left. From what I have read and heard though, it seems to be based on the idea that the dojocho has some sort of mystical knowledge, and every student should suffer abuse in order to gain his ability. I would actually equate abuse in the dojo to that of a cult, and abuse in college sports due to an obsession with winning and the fact that the players are not, in the strictest sense, free to leave.