Popular Mechanics has a short and revealing interview with New Urbanist planner Andres Duany on Smart Growth. The interview focuses primarily on promoting the Smart Growth Manual, a book he coauthors with Jeff Speck and Mike Lydon.
Libertarian and free-market criticism of Smart Growth (appropriately) focuses on the top down nature of planning and its implicitly (and often explicitly) coercive nature because it buys into the progressive view that government does good if the levers of power are in the right hands (re: New Urbanists). That said, we shouldn't lose sight of another aspect of New Urbanism and many New Urbanists that shares common cause with those on the free market side when it comes to the role humans play in solving environmental problems and challenges.
From the interview with Andres:
[ANDRES DUANY]: We [Duany and his co-authors] were surprised to see Suburban Nation ending up in high schools—it was a little subpar for a college text. We were thinking the Smart Growth Manualmight work well as a video for elementary school children.
PM: Surely you could do better than The Story of Stuff.
AD: It's so reductive! Kids are being taught "nature, nature, nature," so much that ultimately humans are the problem, and urban environments are the problem. Eventually you begin calculating the ecological footprint of every American child, and it's a disaster. If all the tools are nature, and humans can do nothing, you could see the destruction of urbanism—and then you end up with more suburbs.
If only New Urbanists understood, let alone valued, the freedom implicit in the market economy, and held a more skeptical view of political power!