Agents' raison d'etre is to make as much money as they can, and many will resort to any measures to sign players who will give them maximum bargaining power with NFL teams. Money and expensive gifts are the best ways to attract players. The dire circumstances of most players make them easy targets for fat wallets. They see other students living the good life. They cannot earn legitimate money if they want to.
Game day is devoted to the game.
If they travel out of town to play, the entire weekend is devoted to the sport. The entire student body benefits from the sport. When I was a graduate student at the University of Florida in the early 1980s, for example, proceeds from Gator games literally bankrolled summer school. The money was a godsend because budgets were tight. Football is a plantation.