Brian Phillips has an excellent post on Houston’s success because of its’ lack of zoning. Writes Phillips in Planning Versus the Central Planner:
What they are really denouncing is the fact that Houston has developed without a central planner. […]Houston’s development has been guided by millions of plans and visions. Each individual has his own plan and vision. Through the lack of zoning, Houston has protected the freedom of its residents to pursue their personal plans and visions. The critics resent the fact that Houstonians have this freedom.
The entire post is worth a read.