Anyone who visits China, even as a tourist, cannot deny that knowing the language is important. If nothing you would want to understand what the tour guide is talking about. You say, sure you can understand Chinese but not speak it. I know of some Chinese Singaporeans who cannot speak it, nor understand it. But of course, touring a country without knowledge of the local language is generally ok provided that you have a good guide.
But increasingly, many Singaporeans are heading to China for different purposes. To visit the country for business and for work. Some are there for educational purposes, to jiaoliu, for community service, etc., when a person stays at a stretch of 10 to 20 days. You would want to know how to speak the language, although writing is not quite necessary. But my experience last September was a real clincher for our attitude towards the language. I had met a teacher at a vocational institute in the course of the visit, a young man. He kept conversing in English with me. His English was already good, but every time I spoke in Mandarin Chinese, he would always reply in English. It isn't that this person doesn't know Chinese, just that he wanted very much to practise using English, to help him improve on the language. I, on the other hand, wanted to speak the local lingo in the land of its birth. But eventually, I settled on speaking in English with this chap, seeing how persistent he was in conversing with me in the language.
It is said that some China Chinese have become rich and they are traveling the world as first class travelers (stay in first class hotels, first class shopping, etc.), but many of them are becoming conversant in the international language of trade and commerce - English. I thought, if we don't work hard at their language (which for the Chinese among us, is OUR mother tongue), one day, they will dominate us, even if were are Singaporean Chinese.