International relations rely on a lot of hot air and misplaced confidence. Most of the world's currencies are fiat, which means that they are backed by nothing more than the issuing country's governmental authority. Hot air. If a country begins to take actions that the others view as destabilising, the consequences for said country are not difficult to extrapolate.
Singapore lives and dies on the much maligned phenomena of globalization. As it gently, and not so gently as the case may be, screws other developing nations out of resources, Singapore thrives. It does so because it currently fulfils a role absolutely necessary to global trade. International monies flow to Singapore because of its willingness to provide this service and independently of the ability and function of her citizens. As a consequence, most Singaporeans are engaged in service related industries.
Singapore is a welfare nation. Her prosperity depends on international confidence and the ruling party's ability to deliver it. This is similarly true for countries such as Australia and Saudi Arabia. Few Australians have ever visited a mining town, but ironically that is where their prosperity ultimately flows from.
Even if every foreign talent imported were actually a burden upon Singapore, the practice is still a positive exchange for Singapore, since she depends upon the good will of richer nations. If some backward thinking troglodyte does manage to get into power and close Singapore's borders, then you should prepare yourself for trying to feed the second most populously dense country in the world with fifteen square kilometres of agrarian resource. Good luck.
I myself persist in Singapore because of family and the sure knowledge that I could find idiots like you distributed evenly upon the face of the earth. My wife and two children are Singaporeans and I would not be surprised to find many others on this forum in a similar position.
I like the foreign product handle, he's creative! Though he doesn't know the import & export regulations