There is definitely a drug sub-culture in Singapore. I lived there for most of the past three years - yes, it is clean, safe, with low crime rate. But brushing aside the very effective and tight government media / image control, one will see that
(1) there is a drug sub-culture in Singapore, it's not severe or obvious like having crack addicts on every street corner, but it's there as a real presence (you wanna see pills traded in semi-open? Go to Rave parties like Zouk-out in Sentosa, the club scene in Clarke Quay and Tanjong Pagor ... etc.)
and (2) it's an on-going, sometime uphill battle for the Singapore Central Narcotic Bureau to control the drug trade in Singapore.
In fact, one of the biggest news / scandal in Singapore last year was the bust-up of a well organized cocaine and heroine network - the CNB rounded up 23 people on suspicion of drug trafficking, possession and consumption. And the 23 included some of the biggest society names in Singapore such as the alleged ring leader Max Oh, a well known event marketing planner, Cheryl Fox, a news reader at Channel NewsAsia, Singapore Tatler magazine's then editor Nigel Bruce Simmonds; Bobby Rubino's restaurant marketing manager Guiga Lyes Ben Laroussi; and Dinesh Singh Bhatia, the son of former Judicial Commissioner Amarjeet Singh and former Nominated Member of Parliament Kanwaljit Soin.
One of the under-current of foreign protest against Singapore's supposedly zero tolerance drug policy is that while Singapore do catch and hang the foreign smugglers, they are far more tolerant of domestic offenders - especially those of more privilaged background. for example, none of the aformentioned 23 will meet the hanger's noose, some got off with a mere slap on the wrist, some got sent to treatment centers, there were prison sentences, but no hanging.
Thanks for relating your experience in Singapore. Sorry to hear those rich kids got off so easy. IMO, it sends exactly the wrong signal and virtually guarantees more of the same.
As for foreign visitors, if they don't like being executed, maybe they should stop trashing the host country. Singapore is an important transportation/financial hub. As such, it could quickly become infested with major drug trafficking and all the corruption that comes with it. They are wise to make the place as inhospitable as possible for anybody who brings drugs through it.