Urban sprawl is a relatively new term, but it is not a new phenomenon. The Free Online Dictionary gives the American Heritage Dictionary of the English Language's definition of urban sprawl as "the unplanned, uncontrolled spreading of urban development into areas adjoining the edge of a city." By that definition, urban sprawl has been occurring since the development of agriculture first enabled people to build cities at the dawn of civilization.
Most ancient societies, particularly those at the eastern end of the Mediterranean Sea such as the Assyrians, Babylonians, Egyptians, Greeks, Hittites, Persians and Phoenicians, built cities surrounded by defensive walls. As a city's population grew, the poorest would no longer be able to afford residences within the wall and a ramshackle spread of huts and lean-tos would grow up outside the wall, the very essence of urban sprawl.
In today's world, urban sprawl is more often about money. It is more profitable to sell farmland bordering a city to developers to turn into sub-divisions then keep it as farmland. And this is perhaps the most significant and important criticism of urban sprawl.
Most cities were founded before the introduction of motorized transportation. They were therefore built where water-based transportation was feasible, on navigable rivers or where such rivers met the sea. Such locations gave the added bonus of being surrounded by highly productive farmlands with rich soils built up through periodic flooding of the river. The settlements themselves were usually built on high ground while the surrounding flood plain was farmed for food crops. The most productive farmland available to human society is still located in the regions surrounding many cities; with the world's population still growing rapidly, we need as much of that best farmland as we can get. City expansions, whether urban sprawl or well-planned and structured, are robbing us of quality, food-producing land resources.
When urban sprawl is controlled and implemented by developers, it is fundamentally profit driven. As infrastructure is usually hidden from sight, it is often underfunded and poorly designed. Water supply to and waste-water away from a development may be simply tacked onto the piping infrastructure of the neighboring development or suburb with no actual assessment made of the requirements of the new development or the capacity available from the established.
By the time problems arise, such as bursting pipes leading to land subsidence, the development company has been terminated and the developers have taken their proceeds into other ventures. Thus avoiding their responsibility for the problems they have created. Local government and its rate/tax payers end up having to foot the bill for major repairs and expansions to the infrastructure.
When such developments are intended for the wealthy they are usually aesthetically pleasing, when intended for middle-income earners they can have a uniformity that is not. They also tend to be all residential, so the inhabitants often have to use cars for transportation to meet their every need: to get to work, go shopping, travel to the doctor/dentist and reach entertainment and sporting venues.
City expansions need to be upwards, so the most productive farmland can continue growing our foods, and they must be planned so those making the profit are also those paying the cost of the necessary increase in infrastructure to support the expansion. When expansions are into the neighboring countryside, they need to be regulated so they provide local parks and facilities for the inhabitants.