I'm with Tilt.
I also take it that there is no such thing as unavoidable HOs. If someone forces the other guy to go into a head-on angle with such perfect timing that there is no time to maneuver out of that way, then by all means that itself is a result of being outmaneuvered. Also, if one tries to move away from the HO by maneuvering aside, but the other guy still forces a shot in then by all means he deserves that kill.
That being said, my take on the original poster's question is this:
...
Sometimes HOs are indeed frustrating.
The basic premise of combat maneuvering is to survive and shoot down the enemy plane without being shot down yourself. Therefore, anybody who takes a certain bit of pride in his skills, has a basic mindset to respect those who also try to fight it out the right way. The two opponents slug it out in a test of skill, both trying to not get hurt, while hurting the other,
However, being a game, it is undeniable that there are a considerable number of people who's entire premise of airborne combat is to shoot down the enemy by any means necessary - if it means one's own death. These guys don't fight to survive. They pay no attention to one's own survival, and their prime objective is to shoot down the other guy no matter what happens. It doesn't matter if it's a stupid or suicidal move. They just don't care. They will point straight to the enemy and hold the trigger down, submitting themselves to the mercy of lady Luck.
Now, against these kind of people, the normal concept of ACM doesn't work.
People who believe in ACM assume that both people are trying to live, to fight it out without being shotdown. So they expect a certain enemy to move in certain logical way. They move around, maneuver themselves carefully, and put the enemy fighter into an E-deprived position. They prepare to go for the final kill.. and what happens is the enemy doesn't try to evade or escape your shots, as he should, if he was a pilot of a sound mind. He just flat turns as tight as possible and comes HOing your way.
Normally, in real life, people don't do this. Even in games, people who have an proactive mind about achieving victory through superior skill, don't do this kind of stuff. Unless there is a certain amount of reasoning behind taking such a great risk, ( ex.. You are hounded by two 109s in a P-47. You figure your chance is to kill one on the first HO merge with superior firepower, and duke it out with the remaining one..) people are supposed to try to live - and that's when they come predictable.
But the HO guys are unpredictable. They have the balls to do this kind of stuff because they know they don't die. In one word, it's "gamey" - something that would rarely ever work in real life, but only possible in a game.
...and that ruins the aura of combat for many people who believe in skill and ACM. They are suddenly rudely reminded that this is a game, and all your painstaking process of learning and practicing real-life tactics, can be so easily nerfed by some twit in a uber plane who doesn't give a shi*.[/color] The whole ACM concept was borne under realistic conditions for realistic engagements... but how do you fight a guy who flies unrealistically, and unwilling to survive, with ACM?
He turns to get a HO angle everytime you go for a pass, doesn't even try to evade, coming straight at you guns blazing.... This isn't such a problem if you are flying a good maneuvering plane like a Spitfire, which can evade, and a few more maneuvers can land behind the tard 400 yards out.. but when you are in something like a 109 or a 190, against something like a Spit16... to shoot him down you are forced to try a HO yourself. Either that, or choose to dogfight him to stall speed so that he is squeezed off every last bit of E and can't try the same stunt again.... and yes, you must risk doing it in a plane known to be difficult to manage.
So basically, when facing a HO tard with a plane that needs some basic disicipline to maneuver, you are almost always faced with a HO. You can always move out of the way, but no matter how you try to gain a safe shooting solution, he comes again facing forward, guns blazing, giving no shi* about survival, no concern for ACM, no care about skill.... and the prospect of the whole attack sequence being stopped and ruined, and sometimes even shot down, by such gamey dweebs, can be just so whoopeeed frustrating.
It's along the same lines as people hating 2k suicidal deck buffs, suicidal jabos, and "side-winder" pilots.
ps)) "Sidewinders" are those who have pretty decent skills, but flies in a guided-missile attitude.
These guys don't care about teamwork nor survival. It's the kind of guys who fly N1Ks or Spit16s (huge ammo or uber gun), picks a target, and follows it all the way up the vertical, spraying bullets like Florida squall, and then gets blown out of the sky immediately after shooting you down.
They know that there are many enemies nearby. They are skilled enough in 1vs1 maneuvering. They have good gunnery. But despite all that, they follow you up the vertical, and don't give a shi* about the dangers of being blown up by other enemies. Just pick a target, and do whatever needed to shoot it down, regardless whether they themselves are shot down in the process.
Normally, one expects a smart pilot to refuse following an enemy plane up when there are more enemies nearby. But they just come straight at you. He's doing what you would never do, and what one would rarely see in real life. He doesn't care if he lives or dies, all he wants to do is shoot you down.... and fighting these guys can be frickin' damned annoying. Like the HO tards, Sidewinders are made possible only because this is a game, and people don't really die in it.... and that also means being ridiculed by gamey dweebs.... which sucks.