I'm still of the opinion that although the HO is dangerous, of a lower skill level, and seen as tasteless, it's still a legitimate option, and should be considered as a threat and allowed for in any fight.
I don't do it, because I see it as a too-low chance of survival. I don't teach it, because I think there are much better, higher-skill and higher probability-of-success options, and because I think it's so "instinctual" - such a basic attack style as to not need teaching. I see it as legitimate, but I don't use it mainly because I prefer to land my kills more often. I avoid it because I'm greedy- I want to kill the other guy safely. I see avoiding the HO as smarter, but definitely not braver, more "right", or more "valiant".
If I get HO'd, I generally see it as "Shame on me- I let that bozo get away with such a basic shot I could/should have easily seen it coming and allowed for it. How foolish..." If my opponent can end the fight as quickly and easily as that I need to work on a few things...
If out flying your opponent is the goal, why is it? To show dominance or skill over your opponent? Outwit him? What better way than to kill him quickly at his first weak moment, his first mistake, the first time he gives you a kill shot? Why bother to fight him at all if he can't look out for the most basic attack there is? ACM is great, but why should you get to display your mastery of it if your opponent can defeat you before you even start?
HOing bombers? Why would it be any more/less legitimate? What if I'm strafing a GV or PT boat? Is HOing allowed then? If the GV or PT boat is shooting at someone else, is it cherry-picking? What if the bomber is shooting at someone else? Cherry-picking again? Does ganging apply to bombers, GV's, and PTs? Should we wait our turn, and attack bombers individually from co-alt 6 O'clock?
Keep in mind when discussing tasteful, legitimate, attack options in AH, what aerial attacks are all about is shooting someone where they're weakest and least able to defend themselves. That means shooting bombers in the face or from above, and shooting fighters in the back. Historically, shooting someone in the back was the act of a coward, not a valiant warrior. It's interesting how that's been reversed. I'm not saying I don't like it that way, it's just kind of humorous...