A PKer is a player who goes out and actively seeks easy kills for their own satisfaction, like a solo Ganker. That is how I have always seen the term, which is been quite a long time. If the definition has changed over the years, I guess I can use a different term. Pick apart my post how ever you like.
PvP is player versus player. My play style is more CvC character versus character. I won't hunt you down just because you seem to be an easy kill or are just there unawares.
No one likes being the target or attacked unawares with no chance of survival.
If we meet in combat and I inexplicitly happen to defeat your character, I won't gloat over your character's body, nor will I loot your prized possessions. I am more likely to watch over your body until you can recover and send you on your way.
But someone who constantly grief kills me, my friends or my tribe, then my character might not have the same compassion.
When I go into wild areas, I expect to be ambushed, but it doesn't mean I support the PK-Griefing play style of some other players.
Woo Hoo! I got the 15000th post!