Being a manager is a huge responsibility. Even if only one employee is reporting to you, you have the responsibility to mentor them, guide them, support them and be vigilant if they are facing any work-related issue. I have seen many brilliant employees whose talents simply got wasted just because they had an incompetent manager.
Work experience does not mean that a person is automatically eligible to become a manager. There should be a serious process to identify the right people.
It is high time that the companies set some serious standards while hiring or promoting someone to the position of a manager. That would be a big differentiating factor between a good company and a GREAT company.