Your post is talking about a very specific kind of attitude— the people who have no interest in the language or hate all the food have no business here in the first place.
Still, I think a lot of people end up staying in China longer than they should. It's always hard to leave a place and start again somewhere else, even if that somewhere else is "home." And in a place as different as China is from the US and Europe, it can be hard to see a clear direction to move in career-wise when you are looking to leave China, further complicating matters. Many people also start to feel like they need to accomplish something concrete before leaving China, and stay here striving or searching for that. It is quite common to get to a point where you feel a little stuck here, and that breeds resentment and frustration. It ain't easy, and we all need each other's support.