If you'd take the time to read what the developers of the game explained, the current system is for balance purposes. Not only would they have to redo the coil system, you'd have people being able to spam for a day and get every myth, tome crafting material and relic+1 item for every class, then you'll also have the community aspect where if you chose not to grind a full day...good luck trying to do everything because even FCs would put that requirement on their members.
Balance. Balance. Balance. We all want everything asap but MMOs usually phase out once that happens.