I agree that a considerate person would listen more attentively if he knew the speaker was not fluent in the language. I am merely saying that it is unfortunate that in 2015 "someone's" face would still prompt this attentiveness.  Many Asian people learning an Asian language are not as readily given the same fudge pass. Actually, that is putting it mildly.

The other part of the equation is that even if someone is initially given this special consideration because he is not a native speaker, the language needs to be mastered... tones and all... consonants and all.. Who seeks to learn a language only part way?

Also, many conversations are not face-to-face.  (Telephone, Skype..) It is delightful when a native speaker does not readily detect that he is not speaking to a native speaker.

I don't agree with the umbrella "asian languages". They are very different and they represent very different cultures.

This is like asking someone who learns english and spanish why they aren't interested in learning finnish and hungarian since they're all in Europe.

It is very reasonable for people to like one language better or find it more useful for their career.

I'm studying Korean but not Japanese, but I still have a few things to add.

First, I agree with the people who've said that most people who study both Korean and Japanese but not Chinese are probably doing so in order to consume Korean and Japanese media.  Most everyone in my Korean class is there because they love K-pop and K-dramas (the exceptions are myself, I'm learning Korean so I can go to grad school in Korea, and two Korean-Americans, who are learning Korean as part of their family heritage).  Similarly, I have a lot of friends who are studying Japanese because they love anime, manga, and Nintendo.  It's not hard to imagine that the two groups would overlap rather often.

Second, I've gotten a lot of negative comments from friends and family about the fact that the East Asian language I chose was Korean.  They think I should have chosen Chinese, since the US has a lot of debt to China, the Chinese government tends not to like the US, and China is growing more powerful all the time - and these are all perceptions they got from the media.  So I don't think that media influence is a factor in causing people not to learn Chinese.  If anything, I think the media influence tells us that we should learn Chinese so that if the Chinese government takes over the US, we will be able to talk to them.

Finally, despite all the political reasons why Chinese would be a good language choice, and despite the fact that so much Korean vocabulary is derived from Chinese (I've also heard 70%), if someone held a gun to my head right now and forced me to begin learning a second East Asian language, I would pick Japanese.  Why?  Because Chinese has tones, and Japanese does not, and I'm certain I wouldn't be able to master tones.

First, and most importantly, your dog is stuck to the ceiling. That's almost as cruel as eating him.

Second, although I haven't started learning Korean yet, I like all three languages. But I admit I like being in Taiwan much more than China. Unfortunately, the communists have greatly reduced the beauty and intensity of your culture. I have several western friends who think highly of the Chinese culture, and it makes me laugh, because if they visit there, their opinions would change dramatically. The culture that they read about is gone.

The Chinese should look at Taiwan as an example of how things could be. By western standards, Chinese are very rude, and that's the main turn off for me. I can take the pollution, the rundown infrastructure and other minor inconveniences. But the herd behaviour, the pushing and shoving, yelling, smoking, spitting and peeing in any social setting is a little too much for me. These are my experiences from visiting China 5 times. I have no idea what the media is spewing.

@Rio - Actually, I like China. I was just telling you why Taiwan is so much nicer of a place. And although I don't think American tourists are nearly as bad as Chinese tourists, I agree that there are lots of bad ones. But I was talking about tourists; I was talking about how you behave in your own country. Have you ever been in Beijing or Shanghai? If it seems like paradise to you, I'd like to know what you're comparing it to.

As others have pointed out, your language learning advice is really bad. Don't learn tones in the beginning - really? This is an example of a native speaker being out of touch with what is required to learn her own language. What you call "stress" in Japanese is actually "pitch accent". What you call "hirakana" is actually "hiragana". Basically, if you mess up the pitch accent in Japanese, you will rarely be misunderstood. In contrast, if you mess up the tones in Mandarin you will rarely be understood.