Personally, I'd rather not tell everyone to quit. That's the worst possible solution to the problem imo.
In many cases, i don't think people are being told to quit because they are having issues with the game. Been plenty of threads where people have stated they are having troubles with the game, don't understand some aspect. Are getting frustrated, thinking about uninstalling, etc. But they post constructively and ask for honest opinions and advice. And they get it.
On the other hand, you get people coming here, throwing their toys out of the pram, declaring they are going to quit... and what sort of response can be expected? Perhaps more maturity could be called for, but i think many do not have the patience to deal with such posts, and instead of refraining from posting, they say things like "Goodbye", "Don't slam the door on your way out" and "Can i have your credits". And i'm not pointing fingers here, because i'm largely talking about my own posts here.
Someone comes, explains their frustrations clearly and politely, ill respond in the same mode. Someone comes screaming and bawling, well, i'm not going to be so polite or helpful. I am British, so sarcasm does come very naturally to me, possibly snark as well.