Very simple, the more language you can speak, the more advantage you will have in anything. I know that since I can speak a few languages.
Malays will always be Malays no matter what language they learn or speak, so does the Chinese, Indians, Kadazans, Ibans or Mat Salleh.
Imagine if you are a very clever in Mathematics or Science but only in Bahasa Melayu, then when you go to college or university and they are in English, then you need to learn everything all over again because you don't understand the terms in English. Wouldn't it be a waste of time??
Nothing to lose people, believe that.