If you want them to stay and would consider it a loss if they left, why wouldn't you give them incentive to stay? Why wouldn't you try and keep the employee? I

If you want them to stay and would consider it a loss if they left, why wouldn't you give them incentive to stay? Why wouldn't you try and keep the employee? If a manager indirectly finds out that an employee is looking over the fence and takes that negatively, then I think it's a bigger reflection on the manager than the employee. Either you consider them valuable or you don't.