I see what you mean, there's limits, and also tough love doesn't always reap rewards.
General practices in education systems and sports is more generalistic (if that's the word, I'm not sure what to use) but these team exercises are less personalised, individualised, sometimes there might be things like dieticians analysing per player their needs or a halves coach, etc, but these trainings are generally provided and conducted to get the common results that have consistently worked during time, some players at that level (and most at the earlier levels) fall through the net. They need different ways to improve and unfortunately the facilities aren't there for them or resources won't be allocated to that level of player. Eventually NRL would enforce some practices for the future for certain players emotional stress etc but Bulldogs might be ok here, we'd assume they tried looking after Topine afterwards but based on the activity it wasn't anything special or he wasn't "picked on harshly".
The whole thing is ugly and silly but lessons can be learned.
If the trainer was inexperienced or had some clear agenda or bias then yeah but to me some elements mentioned and the fact Trent Robinson came out saying some positive stuff about the trainer gave me some confidence this wasn't anything really out of the ordinary.