Playing optimally is knowing how to maximize the resources you have for an encounter. Paeon isn't always the answer. Depends on the group config. You don't wait til you 'run dry' when playing optimally. You slow it down beforehand and go all out when your buffs are available. You plan to run out as the boss dies. Not when it's at 50%.

If I considered going all out 100% of the time the only way to play I would only play Paeon outside of the opener because I burn through TP extremely quickly with or without Goad.

'Sorry, no more Foe's. Gotta be greedy and never slow down my GCDs even when it isn't best for raid DPS.' It's funny because while I would never run out of TP my DPS would be lower. Caster DPS would be lower. If you're running MNK + NIN like we do the MNK wouldn't really see any increase. NIN would gain but not enough to compensate.