I'm not a Catholic, but wasn't the idea of an indulgence that God intentionally allowed an alternative path to redemption, such that if you buy an indulgence, you are (at least by their definition) worthy and deserving?
I always thought of this as essentially the same idea as with Civ allowing you different paths to victory.
I thought Martin Luther's issue was more with the organization selling indulgences than the undeserving buying them. He preached justification by faith alone. Not some org selling justification.
Yes indulgences mean something different in Catholicism, they remit the "temporal effects" of Sin ie its spiritual consequences but don't "forgive" it like "Sacrament of Reconciliation" would..
I think that parent is perhaps confusing it with the sin of Gluttony.
The idea was for the bishop to pocket money and wave a wand and say “saved” after someone with means did something morally embarrassing. It was a racket and also a useful PR tool.
I always thought of this as essentially the same idea as with Civ allowing you different paths to victory.