There was a thread on COTH just recently about a barn like this, posted by one of the riders in the barn who was not being treated fairly, at all. And was trying to understand ‘what is happening here?’.
As you say, it is everyone for themselves, as it were.
There are other sports, workplaces, organized groups, and so on with human behavior problems that don’t really have a solution. Other than leaving.
We are all always in the position of looking out for our own best interests. And taking action to take care of ourselves. But no doubt, some people are better equipped for this than others. And experience is everything – so unfortunately, before running headfirst into one’s first bad situation, one is less prepared for it.
Social media is now providing more of a platform for spreading the word and possibly accountability for a bad rep than ever before. But, SM is a highly-flawed system, and people know that. Sorting out contradictory information means just making some personal decisions about what one considers valid, and not valid. Sometimes without much context.
Newbies to a sport tend to put a high degree of trust in their teachers/trainers. With no real way of evaluating quality. And no accredited reference material to compare.
Yep. 
Plus, as could be seen in the first year or so of this thread, some bad actors are good at finding cheerleaders to take their side on SM.
And in fact, in this case, those cheerleaders became part of the red flags! Their own experiences were – alarming. But posted in all good faith that it was all proper horsemanship. The reader reaction was: No wonder all the problems! But why did the cheerleaders think that all this was correct? Because they had all been taught by the same person that it was correct. That teaching was their only background to evaluate their own experience.
Add to the red flag list (generally speaking) – Knowledgeable people leave the situation the quickest, and people coming in with no background/experience are the ones who stay.