I would argue that good management is critical for a business because it plays a huge role in determining the efficiency with which the business will run and the level of productivity that its workers will achieve.
A major job of management is to get the best out of their workers and equipment. They must set the routine tasks of production up in such a way that they will be done as efficiently as possible -- they do not want to set things up in such a way that they have assets being wasted as they are not used efficiently.
Similarly, it is a job of management to keep morale in the firm as high as possible. Good managers will interact with workers in such a way that the workers remain relatively eager to work. This will maintain the level of productivity in the firm.
Without good management, the firm's profitability is reduced because efficiency and productivity decline.
The basic function of purpose of management is to improve the effectiveness of any work for achieving the intended purpose of the work. As a matter of fact good management, by definition includes all that leads to greater success in whatever work is undertaken by the organization. In this way good management and greater success are inseparable.
The success of work performed also depends on the capabilities and performance of the individuals performing the work. In case of work performed by one person acting in isolation the success is almost exclusively dependent on the ability and effort put in by the individual. Thus we can say that the success is primarily dependent on the technical inputs relating to the particular type of work.
However, for work performed by groups the, the need for managing the complexities of the group working increases and the importance of management rises rapidly with increased size of organization. In these cases the management also has the responsibility for ensuring the availability of right type of technical skill and resources, and for ensuring that the people can and are working effectively. In this way, we can say, that the management is of the organization is totally responsible for the success of the organization.