We may not like it but, the HO is the great equalizer. If you succeed, it puts an end to the skill and ACM advantage some players have earned over time or are naturals at in the game.
That being said, if it becomes the tactic de jur for the MA. Your average night will be, up, fly to the fight, either you out HO everyone there, or for most. Their night is one long repeat of a boring flight to be towered in seconds of arrival. Which will influence many to fly very timid around others and avoid fighting, choosing to only pick, vulch, and run from anyone looking to fight. Kind of like we are now.
The alternative to this which we were closer to about 7-8 years ago. Community peer pressure expressed the feeling that HOing was a bad tactic and players who HOed were bad game citizens, green newbies, or somehow cheating everyone else's opportunity to participate in air combat.
Several in this post are trying to fine tune the definition of what is a HO in AH. The AH definition has always been both aircraft are flying face on at each other blazing away. So everything else in the frontal quarter angle 360 cone is argued over and spitefully defended as skill on ch200, PM's, and here in the forums.
Once you learn how the front quarter cone works in the game, it's an easy kill requiring no ACM because everyone merges at each other mostly in straight lines. If you turn off your tracers, it's stealing candy from a baby because you give no warning for your target to key off or in some cases even know it was you who shot them. Most newbies and many vets shoot long and always miss as a rule. In many cases what has become irritating is the few players who have learned how to shoot during that approach and not shoot long. And they do have their tracers off. It's insulting as heck if you listen to range or watch 200. It's a fast way to have one heck of a K\D and Hit% without needing to invest time in the DA.
Here for newbies and vets is how to teach yourself the shot. You can extrapolate from these instructions for all the other positions attacking from the frontal quarter 360 cone. The root of everyone's mistake. You are not leading short enough in front of the con for the combined speeds of your fighter and the con's. Most often 600-800mph in the MA.
Offline use the AH default.bmp gunsight. It's a 100Mil ring. Use a D9, P51D, La7, or Spit16 to start with. The drone circle has the drones at 3000ft. Climb to 5000ft and fly against the left hand turn of the drones. You do want tracers on as training wheels for getting your stream into the right place. If you turn on the lead computing gunsight the green cross will show you what I'm about to describe.
When the drone is between 2k and 2.5k away dive to it. When the drone is between 1000 and 1500 place the upper edge of the 100Mil ring on the drone so you are shooting down and in front of the drone. This is where you watch your tracer stream and correct it into the drone's path. If you have the lead computing gunsight enabled, you will see that the shoot point for 1000-1500 places the top edge of the 100Mil ring just in front or on the nose of the on coming drone.
The drones in the circle are traveling at about 225-250mph with you diving at about 375-425. In the MA you and your con will be much faster closing. So your aimpoint to lead in the MA will be closer to the top of your windscreen at 1000-1500yds. This is why newbies and many vets miss most of the time with their front quarter shots to an oncoming con. And yes it is a skill that takes some practice. Still it's easier than learning ACM if all you want to do is dive in, shoot, then run, until you can turn around and repeat.