I think the thing about the Relationships Board is that it is heavily skewed towards showing bad relationships, merely because it exists. People aren't going to post about good relationships in there, because there is no need. People do occasionally post light-hearted threads in there, but more often they go in chat, because really, that's where they belong.
So yes, the Relationships Board is likely to see heavy usage of the words abusive, controlling etc. - because quite often, those are the behaviours being shown. Equally, many of the threads on the Relationships Board are going to be from partners (mostly women but not all) who are suspicious of their partner, or who have found out that they are seeing someone else. People who have been through that experience will indeed post in a "projecting" way, because that's really all they can do - offer their own experience to show similarities (or differences).
Yes, LTB is often suggested too soon, but not always. Yes, "abusive" crops up more and more - but then more and more behaviours are being termed abuse these days! Shouting - that's abuse. Pointing aggressively = abuse. Ignoring people and sulking = abuse. Where the definition expands, so will the usage.
I have to admit that calling the OP of the camembert thread "controlling" was ridiculous, though!
As far as the non-Relationship Board threads are concerned - yes it's getting a bit much when people post in anger/distress about a single incident and get told "he's abusive, he's controlling, he's toxic, LTB" - but I haven't seen as many of those as I have seen where the OP starts with something relatively inocuous, but that's just the tip of the iceberg. They can talk about something minor/tiny, because that's "safe" - but talking about that leads to the slow revelation of more information that paints a much bigger picture of the OP's life - and then some people will pick up on that and realise that the OP's situation is actually a lot worse than at first seemed.
At this point in the thread, the OP will generally say "no it's no like that, it really was about the toothpaste lid" OR they'll start to reveal more and more "evidence" that actually, they are in a bad place.
I'm probably one of the accused "armchair psychologists" but I still think that it's important to give people information that might help them to better their situation; and I believe that it would be next to impossible to make a poster believe that their OH is an abuser when he clearly isn't.