The Babas were favoured by the colonial govt because of their facility with English. There was a pecking order in the civil service then: Ang Mo, Eurasian, Baba Chinese, Indian, Malay.
The rest of the Chinese (under 3 generations) were known as 'sin kek' (new guests) Chinese – they were either merchants/traders or coolies/peasants fleeing hardship in China. They were only conversant in dialect, Mandarin (educated in Chinese stream), some pasar Melayu and broken English.