Can a manager afford not being a leader?

From the times of the management and leadership doyen, Peter Drucker, or perhaps even before that, differences between managers and leaders have been talked about and studied. Very many observations have been made, and are still being made, on how the two are different, some of them as follows :
- While managers are efficient, leaders are effective.
- Managers do the things right, whereas leaders do the right things.
- Managers take care of the bottom line, leaders build businesses.
- Managers ensure profits and the leaders continued profitability.
- Managers are for the short term, whereas the leaders for the long term.
- Managers climb the ladder and the leaders point out the right wall to place the ladder against.
- Leadership begins where management ends. And so on and on…

Managers, with the rarest exceptions, have with them teams of employees working to achieve their parts of the organisational objectives. And how can the managers get their teams to stay focused on the team objective and function at their most efficient level if not by leading them? Even if the manager has only one staffer with them, they have to act as a leader in relation to that staffer. To be successful, the manager has to be a leader, and a good leader at that.
I would, therefore, hold that the terms ‘manager’ and ‘leader’ are not mutually exclusive.