There are many reasons to criticize Adam Smith’s model of capitalism, first because when he defended his ideals the world was a different place, most of the people worked in farms and as craftsmen and practiced trade. When the industrial revolution came, capitalism changed deeply.
Adam Smith defended the idea of demand and offer, that would create an invisible hand that would balance the market. But the Industrial Revolution came and changed the world deeply, the laissez-faire is not a good policy because it makes room for abuses and makes disparity grow in society. Because of that, the regulation of capitalism by the government is very important so social equality is achieved.