And that's why asked what you meant by "balance".
You could have meant Rabbit Hole should, "Be fair to the quoted forum", and publish lots of quotes that aren't about obviously abusive behaviour.
Or you could have meant, "Be fair to estranged, abusive parents" and publish lots of quotes by estranged, abusive children.
And so on.
Whatever you had in mind, it is NOT incumbent on a scientific study to provide balance. It is incumbent on a scientific study to state exactly what question it was asking, and how it went about it, so that readers can assess what they are being told.
Eg, what do you think the "balance" would be in a scientific study of how many children died in Bristol of septicaemia in the year 2000? Would the balance be the number of children who died of septicaemia in York? The number who died in 1900? The number who died of heart disease? The number of adults who died? The number who had septicaemia but survived?
No. The study tells you what precisely question it asked. If you want to know the answer to a different question, you're welcome to ask that yourself.
None of which is anyway relevant to this website, which as you correctly point out is not a scientific study. None of which means it can't be read for what it is: an informal qualitative analysis of the behaviour of self-selecting groups of people in their own words.
I'm cool with that. I found it interesting, informative and thought-provoking. I'm not going to be putting anyone in jail on the basis of it.