Rather than learning from our mistakes, foreign countries are basking in the ephemeral wealth of stupidity. We've learned that isolating land uses tear apart the social fabrics of cultures, and as cultural anthropologist Wade Davis puts it, with the loss of culture and the connective tissue it provides, "chaos and madness are left in its wake."
The deeper issue is one that is rooted in socio-economics. Building neighborhoods that aren't communities, but "neighborhoods" as pure product of economic equation lacking all the form and function of truly functional economic communities, but more greatly resemble buying a t-shirt off the rack are another form of pyramid scheme, impoverishing the commonwealth for the benefit of a few and exacerbating a wealth gap creating the instability that is ripe for the types of scenes we saw in Mumbai a month ago.
But, in these times (hell, even in good times) architects (and I'm including all service professionals in the "city" building industry) don't ask the tough questions or steer clients in the proper direction. They just do...a lot like prostitutes.
edit: here is the comment I added to the article:
Actually, I should add that architects aren't spreading it in so much as they are failing in their responsibilities to steer clients in a more positive (and responsible) direction. They are merely prostitutes providing services to developers who are merely providing product (a heinous product at that).
The underlying battle is an economic one, quantitative growth vs. qualitative. Quantitative, in terms of urban development is only responsible with a proportionally growing population. In the US, we quantitatively grew, ie sprawl, without the requisite population density to support it. It was robbing peter to pay paul and calling it economic growth.