Yes, I do know what a will save is, thank you. A raging barbarian gains "that thing you train when you study magic" then? Or does he train his rage to specifically get that save bonus? No. He resists fear better because his rage literally makes him more fearless. This is caused by fury and anger, not arcane conditioning of the mind. Your view on will saves is unnuanced, as there clearly are warrior mindsets that should help out with this kind of thing. And since there are such things, I question the logic that warriors are easier to spook than casters.
Warriors aren't easier to spook then casters. PURE fighters, however, don't train their mental resistances that much.
You claim you know what a will save is, but you then immidiately state "Wait, no I don't." Barbarians can't be feared because they're raging. Is the straight fighter raging? No?
Then why would he be immune to fear?
Will save is "My brain is protected." Fortitude save is "My body is protected." Reflex save is "My reflexes are protected." Barbarian the class doesn't have high well saves. They can't resist magic better then a fighter. They can just put themselves in a mindset where they become a near mindless killing machine.
I'm still not understanding your logic. It seems to be "Fighters should be fearless because I say so."
Hmm...I'm not the biggest D&D fan or even someone who plays it that often so I could be wrong but is Will the thing Wizards use when they study magic? I thought wizards want a high Intelligence. Intelligence is used for numbers of spells, arcane knowledge, spellcraft, etc. not Wisdom/Will. They're mages not Green Lanterns.
While it is Wisdom, not Intelligence, that advocates will save, certain classes have different saves. Wizards have only will, because their entire focus is in their minds. So their minds are protected. Monks have good saves across the board. Again, it fits - monks train themselves for inner and outer balance and perfection. Barbarians have only a high fortitude, because they're all about the brute strength of their body.
Also, while I am also not a big advocate of the Fear Aura magical effect unless its atmosphere is handled well in the context of the game, it is a power, an unnatural, magical effect that I view as not too dissimilar to charm. Instead of charming someone to think you're right or do what you want, you're charming them into fearing you.
That's basically what it IS. As I explained earlier, it's not the monster saying "OOGA BOOGA!" It's the magic reaching into your brain, shutting down everything, and then cranking the fear knob to eleven. The entire argument seems based around this concept of "MY CHARACTER IS THIS BRAVE AND AWESOME FIGHTER WHO SHOULD NEVER FAIL AT ANYTHING."