As a practical matter, students with divorced parents are more likely to be at a disadvantage here compared to students with married parents:
a. Yes, custodial parents may be uncooperative, and this is a risk for students with both married and divorced parents.
b. However, students with divorced parents need to gain cooperation from each parent separately, which lowers the chance of success compared to students with married parents who are more likely to be on the same page.
c. Many divorces are nasty, and the parents who went through a nasty divorce are more likely to be uncooperative to spite each other (or avoid leaking their financial information to each other), even if it severely limits their kid’s college choices.
d. Even if the divorced parents are fully cooperative, they are likely to have less money to contribute, since maintaining separate households costs more (combined) than the shared household when they were married.