You are only seeing things from one point of view, say you are looking for a quick heroic you ask in trade for the last dps spot two people whisper you, one you know one you don't, you naturally invite the one you know. This is where the problems start to arise unless you are part of the group it is difficult to become part of it and without being part of the group it is difficult to run any heroic or raid content. This is why they had to introduce LFD and LFR.
In my experience calling people out creates just as many problems as it solves and it is all forgotten in the space of a few days. I do not think what results to bullying people out of the game is very helpful or desirable.
The subs were lost during Cata not MOP, the majority during difficult period at beginning, many of those that left were so called casual and a lot of them are not coming back. Perhaps the casuals do not share your view on what is easy and what is not? Perhaps they do not agree that wiping in LFR is enjoyable?