All the analogies are bad. You should be able to fund the studies of future generations without retroactively changing rules that applied to past generations. The correct analogy would be: why do you pay the guy who didn’t work last weekend retroactively for those days they didn’t work, if I was actually working: now we both made the same money and I worked 2 extra days for it which is unfair.

Disclaimer: my education was at no cost to me and I never had student debt, I have no skin in the game. The conversation should be about how we help tomorrow’s students, not about giving money to an arbitrary set of yesterday students.