The way I look at it,
Real life was "Kill the enemy" sometimes at all costs.
In the game, there is no kill the enemy, because no one dies. In the game its suppose to be about the "combat" and a ho/joust isn't combat, it's just a waste of time and electronic pixels.
How is it not "combat" (in the game sense you're using)? You're shooting each other until one or both are "destroyed". Sounds like combat to me.
What you mean is it isn't courtly, honorable
dueling. That's all nice I guess, but I would say less than 10% of the encounters I have in this game take the form of dueling. Take the exceptions WMLute listed and add a few others (vulched on takeoff, jumped by a picker from 5k+ up while you were fighting someone else, jumped by a faster plane when you're already past bingo fuel and just trying to get home, attacking or defending a base, or in the middle of a furball with 8 or 10 or more planes on each side), and you no longer have exceptions, you have the rule. Co-alt, co-e merges into 1-1 duels are the rare exception.
That doesn't make HOing a good move in every one of those situations, but it means most of the analysis here, which is based on those mythical 1-1 honorable duels, is BS. And the "bad habit" is expecting and acting like the other 90% of the game is one of those mythical courtly duels and whining when it doesn't turn out that way.
For example: if I'm 10' off the runway taking off and barely have enough speed to maneuver or zoom at all, and you come screaming in to vulch me and are dumb enough to do it from an angle where I can possibly get guns on you for half a second, damned straight I'm gonna HO yer schnoz and laugh hard if I succeed. That's all your fault for turning a situation where you have every possible advantage into one where you have the same chances I have, and taking the best shot I'm likely to get is the smart move for me. There's no magical ACM or "pile-it stuff" that I'm neglecting that's going to give me an advantage after that "merge," and there's no duel for me to engage in or avoid.
And that goes double, or maybe triple, if I'm defending a base so I know that if I get shot down I can just up again in 10 seconds while if you die you've got a 10-minute flight to return. In that situation a success rate of 1 in 10 is still a win in strategic terms no matter how disastrous it is to my score, because I've accomplished my objective and you have failed at yours. Is that logic like real life where you only get one life? Of course not, but then we've already agreed that this game isn't real life, haven't we?
The situation in a big, messy furball is different but similar logic applies. If we're both maneuvering with other planes and all of a sudden I see you about to go nose to nose for a split second and give me a snap shot, I'm not going to pass it up because it isn't "honorable," especially if I think you're target fixated and won't see it coming. And chances are my maneuvering after the shot will have nothing to do with you whether I succeed in killing you or not anyway, I'll be more concerned with whoever I was engaged with before we stumbled into each other. This has nothing to do with wanting to avoid a "fair fight" in the sense of an even duel since nobody involved is going to get one regardless. It's just a reflection of the fact that in a big, complicated fight ACM takes a back seat to SA and gunnery.
Of course those calculations have nothing to do with courtly duels, but then if you're only interested in fighting courtly duels then you won't be over my field trying to vulch people taking off or in the middle of a 20-plane furball, so you don't have to worry about it.