LKY just wanted to erode the deep-rooted Chinese culture back then because they were giving him a hard time while he was in power. One Lim Chin Siong was probably more than he could handle, he could not afford another Lim Chin Siong who can galvanize the traditional Chinese votes (then the majority). So he started destroying the Chinese culture for he thinks they are the future huge hindrance to his reign.
Therefore, the English as compulsory first language kicked in to "Anglonize" the local Chinese and make them have the same thinking as him to reduce opposition. Learning English is a good thing, but the reason behind it is bullshit. Hence, "White is Might" is born.
I doubt it is to unite all races under a common language. Many other nations have the minority learning the majority's language and most do not face any racial issues. It has nothing to do with business at all. Japan, South Korea, PRC and ROC managed to grow even though they emphasize on their own mother tongue first. The businessmen do not care about whether you speak English or not, so long you are cheaper. This is the reason why many businesses are going into PRC to set up factories, the average PRC worker cannot even speak a proper sentence of English but the ang moh boss don't care. He got the middleman who can translate instructions.
If you look at LKY's life, you know that he is not your typical Chinese. He is those Western-minded Chinese who look down on the normal Chinese just because he is good at English. He probably never liked the Chinese culture in the first place. And if you noticed, he only emphasize on how important Chinese is recently, when PRC is rising.
