I'm American and lived for the past 10 years in one of the US's more crime ridden cities, so I just console myself in the knowledge that whatever Asian country I'm in is no more dangerous than home. Sure, I'm a foreigner and thus a target for scams, but I've seen them all before. And 95% of petty crime is easily avoided through basic street smarts.
The sensationalistic stories in the ST and other Singaporean media about people getting carjacked in Malaysia, etc are not representative. It's like they say about local news in the US: if it bleeds, it leads.
BTW, your street smarts should be turned on anywhere you go. Including Singapore. You may not need to worry about getting mugged in SG, but there are plenty of other things that can go wrong, and as a foreigner you are under special scrutiny especially in the current political climate.