I beg to differ. Singapore may be right smack among countries speaking some form of Bahasa but prior to its independence, it was a British Straits Settlement and subsequently a Crown Colony for close to 150 years. Malay was only adopted as the national language after independence. Before that, the only official language that mattered was English. Even during that time, you can still get by without knowing much Malay. So it is certainly wrong to say that speaking Malay would be the natural state of affairs on the island.