It’s really nobody’s business who pays for a student’s college. Nobody should judge another family’s value system. If parents want to and are able to save or in some other way, fund their child’s college, so be it.
I think it is sweet that you plan to pay your parents back but I bet they don’t want it. I hope to be paying for my children’s college and all I really want or need in return is to see them successful, happy, and to be a good son or daughter by helping me in my old age (God willing).