Re-Opening old thread I found (now read-only, from last year)
Shoutout @Tadaharu for his original post -
"For those who don’t know, dishonorable kills (DHK for short) was a penalty system intended to prevent high level players from camping important NPCs - civilians (quest givers, flight masters, etc.). You would lose a substantial amount of honor if you killed them. It was introduced in patch 1.5 and removed in TBC.
This system had a big negative (unintended?) side effect, in that it stopped virtually all town/city raids by anyone who was trying to get honor, because civilians were almost guaranteed to get hit by some AoE and the penalties were drastic (see https://www.youtube.com/watch?v=pF9yEZLB9jk).
To make matters worse, it actually never fixed the underlying issue, as those who didn’t care about the honor system could still keep killing civilian NPCs without any penalty. If Blizzard is really worried about people camping NPCs (I don’t think it is that important), please make them untargetable/passive, like children already are.
I don’t care what patch we start with, but town raids were one of the more interesting parts of world PvP, and a common instigator for escalation, and I definitely want to relive that."
As title says, I am an oldschool vanilla player (Despite being 5 years old back in 2004)
I played my trusty Blobehead, right up until release of Wotlk, It took me 4 years to reach level 55 
Back to main topic.
My fav experience during Vanilla WoW or (classic, whatever you wanna call it) was killing npcs / players in towns, in open world pvp, it was such a big thing to form huge parties, even at low levels, and raid a town.
Especially in places like tarren mill, vs southshore, it was by far the most fun thing for me to do as a casual, pvp player.
I hate being confined to being forced to pvp in a battlegrounds for fear of losing my honor rank, and once DHK’s got added into the game I feel it drastically affected my enjoyment of the game.
(not because I’m a griefer who enjoyed killing low level important npc’s)
But 1.) because those npc’s were not properly marked, and it was sometimes unclear which npc’s you could / could not kill
2.) Sometimes you’d get players in your team who did not care and killed those npc’s regardless, and you would get punished for the behaviour of those players.
3.) Players would still come and deliberately kill these npc’s anyway (griefers)
It did not disencourage them at all and in fact, I’d say the type of players who went around to kill those npc’s in the first place, are the same type of players who would enjoy losing honor points for doing such acts.
The whole reason DHK’s was implemented, was to stop griefers from killing important npc’s and effecting others gameplay in a negative way.
(Instead of adding back DHK’s, I feel they should be removed completely)
I disagree that these npc’s should be untargetable / invulnerable, however they should have very short respawn times, so if they did get killed. (whether by accident, or on purpose, it would not effect the playerbase in such a large way)
One of the greatest and most epic moments for me when was when Alliance would try to raid crossroads, and there would be 40-50 alliance turds, running around crossroads 
trying to mess with my levelling, and I would land a killing blow on an alliance scum, twice my level, somehow, or charging them and giving a one second stun, that would help a higher level horde, ally kill him, and I would feel useful.
Really felt the tension of “War” in World of "War"craft, and for me the open world pvp, and open world city raiding was the BEST ASPECT of the entire WoW game in general.
I am not totally against DHK’s.
And would not really be that upset if they are going to be implemented, but I do feel that Huuuuuuge Open World wars should be encouraged, and would make the game much more enjoyable, for a large proportion of the playerbase.
(I mean what is the Local defense, and World Defense channels ever going to be used for, if players are too scared to do city raids as a team, and forced to solo raid a town, or only stick with their 2-3 trusty friends they can trust to go to a city, and not kill (whether purposely or accidently, kill a civilian flagged npc)
this would encourage low level players to run into a high lvl players blizzard deliberately to f*** with them