OPINION: Why PRC hawker couple given Singapore PR? Are they considered as "talents"?

Temasek Review, 27 Jul 2011
The state media reported yesterday a PRC couple Mr Li Wencheng and his wife who were attacked by a mentally deranged Singaporean at their Tampines flat.
Mr Li, 39, suffered injuries to his head, face and left arm while his 42-year-old wife had slash wounds on her back.
In an interview with ‘reporters’ later, Mr Li revealed that he and his wife are running a stall selling fish soup at a foodcourt at Tampines 1 shopping mall. The duo are Singapore PRs.
Do Singaporeans shun being hawkers at foodcourts? Or is Singapore facing a shortage of hawkers?
It is not known how they managed to find work in Singapore and even obtained Singapore PR. Full story