You make some fair points, if I had planned on staying for 7 years I would have made more of an effort too. It goes without saying that its a useful tool for communication but whether its worth learning depends entirely on circumstances. Meeting girls didnt really apply to me because I am already married. If you plan on building a life in China then learning the language is obviously the right thing to do. But if you are only going for a quick laugh its a lot of time and effort for minimal rewards. I got by perfectly well without learning Chinese and I reckon anyone else could too.