Come to Singapore. There's places where there are 7 or more malls all right next to each other and more being built. Kuala Lumpur seems to have lots of shopping centers being built and many of them get full as in the there's no parking left.
Undoubtfully the climate. This leads to Singaporean malls being 100x more interesting, convenient, high-end and better looking than any US mall. Pretty much all large malls have direct or adjacent to public train transport (MRT at Vivo, Ion, 313, nex...), have high-end restaurants, mid-range and fast-food offerings (local and international) and a wider variety of stores. They also have air conditioning, which is pretty much the only reason why all life happens in malls and you can barely walk around on weekends ;)
The point isn't that Clarke Quay itself is a mall (even though the owners, CapitaMall Trust themselves call it a mall...) but that the weather doesn't have to be an obstacle for outdoor shopping.
I was just in Guangzhou recently. Same thing there. In TienHe all of their multiple 6+ storey malls are connected by a sprawling series of underground malls. The shopping there is crazy.
