It's not illogical unless you also find min maxing and trying to be efficient as possible also illogical. You can reply with "but you only need darklight for coil", but a lot of people find their enjoyment in the continual upgrades in terms of maximum efficiency.
Also, too much time? If you haven't noticed leveling in this game is easy. If this was 2004 ffxi I might agree with you, but it's not. This game can be played efficiently with a non-hardcore schedule.