For one thing, in a simulation setting you are able to try your skills out on various machines without the real world need to be on each one of them. It can help you narrow down what you are after in a more expedient manner. It is a form of virtual reality that is both a lot safer and a whole lot more cost effective. Let's face it the cost of the machinery and the cost of the fuel to run that machinery at the initial stages could be quite cost prohibitive and would surely raise up the lab portion of the schooling.
Simulation allows the instruction to give you hazardous things and situations that could cause death if they were real and this way you can see how you do react and learn why that is the right or wrong way before it actually has the possibility of costing in human lives. You will learn the text book responses to these scenarios and by doing so you will be better equipped to handle them as a matter of second nature when they do actually come up on a job.
You will learn how to best handle the controls in a manner that is safe and cost effective to the point that your level of prowess with the machine will increase exponentially to the point of becoming a near expert before you ever actually turn the key on a real machine. Another huge advantage to the virtual realm is that you can have access to these simulations at any time you need them rather than just during normal operating hours so you can log in extra time if you need or want to in order to expedite your training schedule.
Another plus is that while you are learning on the simulation models you will have the ability to hone your skills in the art of communication with regards to operating this type of machine. You need to learn to communicate you actions well to others in order to operate safely in a true work environment and by being on a simulator you can concentrate on them without fear of a devastating accident if you make a wrong move.
As you can see by this point, it not only makes sense to train in and on the simulations but it is going to expedite what you learn and how fast you actually learn it. It will get you ready in less time and it will ensure safer learning and will make you a safer worker once you actually enter the work force on the real thing. The future of training is in the use of simulations, pilots have been doing it successfully for years.