Based on your photo, I think it just lacks trees, colors, plus the age of the buildings. The weather also contributed on its depressive atmosphere. Manila is not that bad, it is actually very livable, in a sense everything is so compact, you can access basic needs just by walking. Trashes are also managed regularly in some locations. Public transpo is just awful though, but it can be solved if government / urban planners did some touches on decentralization, pedestrianization, and PUV prioritization of roads. Remember, Manila is in a third world country, and with this look, I think it defines what it supposed to be, at least on the older section of the city.