Easy test: just go run around lvl 58-70 maps and you'll see tons of dead people, because every hour there are PK 80+ just going to kill everyone they see.
You can't just simply let this happen on a game with automatic farm/lvling system, is just not sustainable. PK in old L2 was OK because :
1.- You actually got a risk for your toon to get PK, once you get too much karma you even rather to lose that chars instead keep playing on it, and god forgives you if someone reahc to kill you you may lose everything.
2.- Old L2 was not an AFK game as it is right now, we usually were alert of what happen with our chars, we were farming by ourselves, that's why the party system was popular, you need active buffe,r active healer and avtive DPS doing whatever they manage to kill mobs.
3.- PK was the last option. Before you go for PK someone, you try to flag them anyway possible, or just send war, but now even when people send war they just don't get other clan must ACEEPT to start the war, they actually believe send war = you can kill them.
You can't just pretend your old systm fits the new featuries you bring to the game, is not compatible anymore, specially when there are people abusing of the failures on it, and making the game unplayable for low lvl people, and more important high lvl players in 100% PVE mode. It doesn't have any sense you are the one who lose items and tons of EXP and time by being killed by a PK. Just NO, he should be the one risking more, not the white names ones.