Why should we if there is a Chinese language we all could use? I used to work in a hotel where I met foreigners who spoke to me in Mandarin. Fortunately I had always loved Mandarin and had done my best to speak a little, so I did not have to say "I'm sorry, I don't speak Mandarin."
我曾經在世界級的飯店中工作過一段時日，每逢遇到外國人對我說起國語，我總慶幸我支離破碎的國語仍組得成一個個完整的句子，慶幸身為中國人的我永遠不需對外國人說：「對不起，我不會說中國話。」