Why can't Managers Edit or Delete KPIs for Direct Reporting Employees?

Managers can only create KPIs, but not edit or delete KPIs related to direct reporting employees (first degree reporting employees). 

Should a manager wish to edit or delete a KPI/review relating to a direct reporting employee, the manager's reporting manager has to be the one to make the changes.

This is to ensure accountability, so that personal biases and the "shifting of goalposts" can be eliminated in performance reviews between managers and direct reporting employees. Managers are allowed to edit or delete KPIs for second degree reporting employees and below.

In the example below, should Jeslyn make a mistake and want to edit or delete KPIs for Colin, she would need to get her reporting manager, Thomas to make the edits on the system using his account.