I'm an MS I cadet and I got mine for an upcoming rotc trip during the summer.
For AFROTC that is why they would offer them the opportunity to get the CAC, because to get on base you need a military ID.
For the OP because they are contracted they should also be doing a summer tour, thus why they would be eligible for the CAC. However, if the OP was not doing a summer tour and not contracted, than it probably would mean that the AF sees no reason to give them a CAC. Remember for AFROTC there is the you must be selected for SFT, if not than they will likely disenroll you from the program. Thus, it makes no sense to give it to every AS100 from a fiscal/manpower aspect, especially if in a year from now they are dis-enrolled which means they have to confiscate the ID.
Sled,
It maybe the AF bases that you are visiting, but I can tell you that not only was it the base that DS got married on, but also was true for his UPT base, his current ops base, and in the area that I live at, it is true for all of the military bases. The only place that it is not true for me is when I visit Bullet at the Pentagon. However, to get into the Pentagon you need someone that works there to get you in.
~ You go through a visitor center 1st, than you go to another area to get a visitor pass, and that is where the sponsor shows their ID.
Years ago 100% ID was different. 100% meant you just show your drivers license and you were good to go. Now, for the bases that at least I have used, if you do not have a military ID you must go to the visitor center 1st and register with them, they will than give you a paper id to present to the guard valid for X amount of time.
~ IE my DS's wedding, we registered them for 2 days (dress rehearsal day and wedding day).