Earlier quoted context omitted.
It's not actually the extreme punishments, it's the consistent small punishments. It's that you'll actually, seriously get a ticket for littering, even if it's a relatively small ticket. The "Fine City" enforces it's vision in a ubiquitous way, so people just don't break the rules.
Don't people feel anxious all the time? I do when I visit certain places like Singapore, where any misstep feels illegal.
Press freedom is limited in Singapore and that is a significant problem for its democracy. As a tourist this is unlikely to impact you. Otherwise, rule of law is paramount in Singapore.