You seem to me that you made up your mind and don't have other choice...
In a way i understand your grandparents, because the bottom line is that education give you indipendence!!!
Does not make you smart or a better pilot but gives you choices, once you get your education and a good job you will have the resources to follow your dreams without asking anyone. Then you can decide to have an expensive hobby or a wonderful flying career. In any case it will be hard and tiring but...very rewarding
This is my opinion.... good luck for your future!