On the subject of chicken whacking, bird stupidity and bird attitudes, I have to say that not every chicken has the same IQ, and not every chicken breed or strain has the same average IQ.
My father had one aggressive and dumb as a rock hatchery Buff Orpington which responded to being waled on by one person, by becoming more energetically vicious to all people, even the chicken feeder. This bird had no hens to protect, just a lot of anger welling up from somewhere. Unusually dumb. Would try to bite (I mean attack bite) your hand and eat corn from it at the same time.
On the other hand, I have a 2 1/2 year old Crevecoeur rooster who has hated me furiously since reaching adulthood. He is a stalker, not at the top of the pecking order and may think he is a Buckeye, due to who he was raised with. A brooder baby from a hatching egg, not raised by a hen as I have been doing more recently. His whole adult life he has lurked in a second-string part of the chicken yard and rushed me on occasions when I am near him (< 30 feet) and my back is turned. He is lightweight and nervous, paces and threatens from a distance by picking up and repeatedly dropping small twigs. I'm honestly not sure of his natural body conformation because he always seems to be in threat stance, wings dropped forward, neck giraffed upward, watching me sideways. I ended up removing his spurs to make the inevitable sneak attacks inneffectual. This is a rooster who is terrified of me but who has spent his life valiantly attacking me anyway. He has had everything tried on him, one approach at a time, each one for a while.
-Ignore him and treat him like the other chickens, toss him food if I'm tossing food to others (default: this is what I've always done between attempts to straighten him out).
-Chase him either at a run or at a walk until he hides or lurks in a remote corner and ceases making belligerent gestures. Tried this one often. Strictly a temporary solution.
-Held him down and made him "submit", kneading his back and for good measure, "pecking" the side of his head with flicked finger tip. Also temporary.
-Carried under arm (this had so little effect he attacked immediately on being returned, dizzy, to ground level. No humiliation for Mr. Mission Discipline)
-Allowed him to attack and showed him that I'm totally impervious to it, reacting as if he is not there (easy enough w/o the spurs). This seemed to throw him for a loop, but not enough that he wouldn't try again the next time round.
-Biffed him rapidly on the side of the head with a dry weed stem every time he approached within attack range (lightweight stem - a fast flick produces a stinging impact but no serious effect). Confused, annoyed and intimidated him, but again, effect only temporary, even while carrying weapon.
-Kicking or self defense with foot (soft shoes - Crocs) only seems to get him worked up, as if he feels that you're finally engaging him in a decent mano a mano fight.
-Chased him and whacked him with a real stick - this only done once, when I was incensed and bleeding from a forehead spur puncture received from side on while crouching to get a better look at some hens. I was worried I may have done some real damage, he ran woozily into a bush then tottered and hid in the chicken house. After he recovered, no net effect.
Very occasionally he has to be caught and tended to, sometimes for prophylactic mite treatment, sometimes in the past to try putting him in different pens, sometimes to deal with medical issues as when he managed to partly snap one of his own spurs by unknown means and was running around with it bleeding and dangling. On these occasions it is clear that he is terrified of me but not so terrified that he also won't also try very hard to bite.
So basically, a campaign of intimidation alternating with indifference has resulted in him convinced that I am an indomitable, vicious monster too dangerous to simply leave alone.
Amazingly I have been making some headway recently after grabbing him, holding him and feeding him irresistable morsels of sweet tree ripe peach. He seems to be staying out of my way now when I'm in the chicken yard. Over the last couple weeks, he has become more and more comfortable with repeated offerings of peach treats through the fence, which he must take from my hand or watch a small hen pal eat instead. Prior to this there was no way in ** he would approach me calmly for food, fence or no fence. Who knows why peach would have more effect on him, I have been feeding him when he is hungry his entire life. But there does appear to be a change in attitude.