Masonry and carpentry jobs have been low paying professions in Singapore since I was a kid. Many parents push their childen to do well in school and have high academic goals for them so they end up with better paying jobs. This has produced a whole nation of architects, doctors, engineers, IT specialists, bankers, and other bookworm technocrats. You will not find a young Singaporean bricklayer, cement-mixer among them. It's not going to change overnight.
Cheers!