It's not about enmity.

Overpower is 120 potency conal AoE with no combo requirement and the only other AoE WAR has besides Steel Cyclone. Since WAR has no means of replenishing TP, Goad fits nicely for them. Granted, it's only feasible to use OP for DPS when there are a minimum number of targets.

If you know your MNK or DRG isn't a clown, goad them all you want. But I assume we're talking about random-ass DF where the MNK has internalized "MNK can't AoE" and the DRG is going to spam 100 potency Ring of Thorns. A WAR really can't screw up Overpower.