Malays, in Singapore at least, are often relegated to the secondary jobs (e.g doorman, bellboy, my cleaning lady when I was living in SIN) . There is a huge gap between Malays and Chinese in Singapore economically (mainly because there are not many of them to begin with)

The Chinese being the majority often have better jobs and education. If you go to the PPS center at the paragon, you will notice that most of them are chinese (by sharp contrast to the agents at SIN or the security people)

This is of course different once you step in to Johore Bharu in Malaysia where the Malays are the majority (with the exception of Penang, which is predominantly Chinese, like Sinagpore)

Some of them (the Malays) do very well in Singapore, but they are few and far between.

Of course they may be a reason other than what I mentioned. I've always wondered why a lot of the security and immigration people at LHR were Punjabi.