Just like Duke basketball, corporate entities run certain systems that they believe will set them up for success.
Usually, when promotions are meted out at other organizations, they are done so after someone has worked there for a while. Their years of service are rewarded in a way that is loyal to the loyalty given. After this threshold is crossed or that hurdle is overcome, benefits are conveyed that often kick in after a predetermined period of time.
There is something to be said for a system like this because the bonds they form, allowed to build over time, can be that much stronger and lasting.