You could say it's a "no free lunch" scenario. There will be a cost no matter what you choose to do. It may be their crew, it may be your crew. It may be your own life, it may be the beginning of a war.
In any case, the ultimate cost is the death of your false belief that there's always a way to come out of every scenario having averted all possible danger and saved everybody, stopped every bad outcome. Every choice comes with consequences, a trade-off.
In a society full of ever-advancing technology which keeps solving all the formerly thought unconquerable problems of yesterday, holographic fantasies, and the ability to outrun your past across star systems rather than simply state and country borders, people tend to think that they can do anything and escape the consequences. That they are in control of their destiny and that of those they care about. (and to be honest, many people already believe that, warp and transporters or no).
Starfleet Academy sees the possibility for greatness in its cadets, but first, it would like to disabuse their false notion that their lives are in their own hands, the myth of control.
Come to think of it, everybody could use a Kobayashi Maru moment to shake them awake. Better they come to the realization through such a simulation than in real life first.