In my experience it is not solo players in need of leveling who behave this way. Players leveling characters are not the kind of people who eagerly go into "who is willing to waste more time" competitions, especially new players who often do not know how PK is implemented in the server and avoid it all together. No, people who abuse the lack of PK exp loss are usually solo players with 3 boxes, full buffs who are farming for drops and adena. Or small groups of 2-3 active players, again with a train of support boxes. In order to get them out of the area you are forced to PK the box train too, which is again, virtually no loss for the guy, but +4PK for you.
I did not and do not advocate the item drop be removed from PK status. That is half the PK penalty for the killer. I think becoming PK should remain severe, if not more severe. My point is that getting PKed should also be severe, you should be encourage to fight back if you want to protect your farming spot, not just stand there and keep getting killed. In what world getting repeatedly killed over and over is considered a valid defensive tactic? My point is - it shouldn't be. If another party comes for your farming spot, you should fight for it. If you're stronger, you hold it. If not, they take it. If you have allies, there's that option. But a single person with a bunch of boxes shouldn't be able to hold an area against a full party or even two parties, simply because PKing them is too much of a penalty and they can keep coming back because there is no penalty for them.