I was only there for four days but from my lofty tourist perch Singapore is everything that almost all other cities in Asia are not. The tap water is fit to drink, drivers stop for pedestrians, the streets are litter free, and English can be understood most everywhere. The people look confident and dress the part. Bangkok has none of these positive virtues. Thailand is a big country with a Buddhist north and a Muslim south and poor people everywhere who are drawn to their nation’s capital and the result is the chaos of car exhaust, crumbling concrete and beggars with every malady imaginable on display behind their begging bowls and filthy dogs and children.
Everything in many Asian cities looks new and old all at the same time. A new shopping development or freeway overpass may have crumbling concrete or exposed rusty rebar. Buildings get stained by car exhaust and rain. It took time, attention to detail, dedication and money to make Singapore look and functions as well as it does. Cities like Bangkok have more pressing needs. For one thing, Bangkok is succeeds in delivering some basic services to its citizens. OK, the water out of the tap isn't fit for human consumption but the Bangkok Skytrain and MTS subway are much better than their counterparts (well, there is no subway) in Kuala Lumpur. They go where people seem to want to go and connect with each other.
Bangkok seems to have been built without electricity and communication by wire in mind so it's been retrofitted on the fly and on the cheap in the most ugly and utilitarian of ways. The wires run amok like someone tripped and dropped a bowl of ramen. I've also seen this in China where wires are tacked up just about anywhere they'll fit. A city does what it can with what it's got. And then there's Bangkok's infamous traffic. The Skytrain and underground rail has helped but it's still the chaos of pedestrian beware. There are plenty of cops out on the street wearing sunglasses and surgical masks but they just nudge things along.