You receive Deferred Action(D.A.) on your case. When applying for a work permit, D.A. applicants have to show evidence for economic necessity for a work permit. That is why it is not automatic, rather will be judged on a case by case basis depending on your reason for requesting one.
Btw, paying for college expenses is not considered an economic necessity. You have to show that you cannot survive if you did not possess a work permit.