Why use simulations?
Simulation (games or make-believe) is the oldest method of learning, preceding the existence of mankind. The young of larger mammals (particularly cats, primates and dolphins) engage in play for much of their time and, in this way, learn to operate in groups. They also learn skills (like stalking) without the dangers inherent in 'real-life'.
Modern flight simulators, on which pilots are trained, are very expensive machines but, nevertheless, they are cheaper and safer than flying real aircraft. Furthermore, pilots can learn to deal with situations which, hopefully, they will never encounter.
Where skills are repetitive, conditions remain fairly similar and danger is not an issue, then real 'on the job' training is preferable - for example, learning to drive a vehicle. (Although there is some evidence that motor-cycle simulators can reduce accidents)
In management, conditions are always changing. A manager who has been successful in an economically benign period, may have learned just that - how to be good when things are easy. But, is it wise to risk the organisation's very existence, if that same manager has not been taught the necessary skills for dealing with adverse conditions?
The value of a simulation depends on how realistic it is. Even so, all factors need not be included - the precise details of the in-flight entertainment system are probably not relevant to the trainee pilot (although they might be for the cabin crew).