Business schools can help corporates grow but not the economy or a country. Managers(MBA's)can help corporates corner higher market share for their companies but in no way can contribute to the overall economy. Unlike popular belief like that of yours they cannot create income but help concentrate the income with corporates which are the fittest.
The world will not see a fundamental change if all this managers from the business schools disappear from the face of the earth.
Teachers, researchers and people from all walks of life with a sense of social responsibility keep the world going in the forward direction. However, these people are the humble beings who struggle to keeping things rolling in the right direction and the so called Business school graduates only grab these towards themselves and corner the glory and the moolah.
In reference to your statement on Managers promoting products and services, it doesnont matter if the a company X and its managers cease to exist, company Y will just do what X was doing with no problem. Its not like the world will end.
