Chewing gum is really expensive to clean up from streets, and they have invested a lot in having nice streets. It's just a cost/benefit thing. It's cheaper to

Chewing gum is really expensive to clean up from streets, and they have invested a lot in having nice streets. It's just a cost/benefit thing. It's cheaper to fine the blood out of people for not flushing public toilets than to pay staff to check in every thirty minutes, and the reduction in costs (and maybe other things) means that Singapore has awesome public toilets.