There isn't really a problem with the mechanics, it's a response to unintended player behavior (i.e. buying relics) for the first relic quest. Yes you have brought it upon yourselves. Now they have made it so that no part of the quest it is possible to purchase services (such as making gear, materia, buying primal runs, etc) and so there is no gil buying incentive. In addition, because a person can no longer just "purchase" the relic when they have enough money, they've restored the meaning of the relic weapon, as a rare weapon that only a dedicated few will get, and only the really dedicated will have for multiple classes.