With in the game it most certainly is. The community always dictates the way most things go, honor included. In AW it was "cool" to have kill macros. The community encouraged it. In AH it is not, those displaying them are ridiculed. Again, the community decided. The same hold true with honor.
It is either in bad taste or it is not. For instance, there are whole games full of people who smack-talk like worst gutter trash, and their communities accepts this. This does not make it right. Thankfully AHII is better than most in this regard.
Why do most people complain about HOs? Because its lame/not honorable, it sounds like the community it trying to speak and set a standard. It's still a big topic, and will likely go on going back and forth for years to come, but its how it works.
Why must we make it a matter of some putative "honor" when I can sit here and give perfectly good reasons to avoid HO'ing? If you can understand why HO'ing is generally a bad idea without making it into a commandment, you will try to avoid it as a bad risk under most circumstances. But you won't have an asinine absolute hanging around your neck, like believing it would be "dishonorable" to HO a Spitfire who obligingly flies directly at your 110G.
Don't confuse honor in real life, with honor in this game. People have to learn to keep the game and real life separate. What passes for honor on the other side of this screen may mean much different things to many different people. The same as "they did it in the war" doesn't carry any weight here because this is a game, NOT real life.
Nope, they are one in the same. If I agree to duel with you with a cold merge and HO on the merge, then I have done something dishonorable. If I meet you randomly in the MA and choose to HO you, I have not done something dishonorable, merely something stupid. I am not dishonored if I fail to follow any rules which I have not agreed to, either explicitly or implicitly by joining the game, as set by HTC. Examples of valid rules of this sort would be no hacking, cable-pulling, shade-vulching, etc.
An example of a rule which is *not* valid and which we have *not* all agreed to follow is the idea of "never disengage from a 1v1 in the MA no matter the circumstances." This is not a matter of honor, it is merely a preference of some players that they wish to inflict on other players, despite the fact that they don't buy the notion.