It is a gift handed down by a rich parent — the parent in this case is the university. There is no difference. Someone is handing you thousands of dollars and they say: “here is some money for your school, in order to keep getting this money, you have to get good grades and volunteer as a teaching assistant.” How is that any different than a rich parent giving you the same money with the same conditions? At the end of the day, some benefactor is handing you a pile of money to get an advanced degree.