Even post-errata, RoB says:
If you’re wielding a flail, a light blade, or a spear and have Dexterity 15 or higher, make the attack a third time against either the target or a different creature.
And if you're don't have the DEX, and are not wielding a flail, a light blade or a spear at least some of the time, then what are you doing with the power in the first place? That's what retraining is for.
My fighter actually uses a trident which is technically a spear but I have to say thanks man! I had no idea I could pick a different target sweet!