Most Chinese people including myself are very proud of our culture especially our language. The fact is that all Chinese people learn English as a second language since primary school. Therefore, imagine in a public occasion, if anyone cannot speak English with a foreigner who will be considered not a well-educated person. Espeacially these days, when education is considered the most essential factor to define the value of every single person.
I forgot to mention that the use of Chinese dictionaries is aslo a huge problem because you need to know the meaning of about one hundred simple characters before you can define their combinations of complex characters that you are trying to look for.
I totally agree with >>28 but I have to say that the vocabularies of Japanese is going kill you.
However, there are also many advantages of learning Japanese. Such as they make good songs and animes and that is unbelievably helpful. Don't forget we learned our mother tongue from TV.