If some one has to type /pvp to close a griefing tactic I'm all for it, it takes 2 seconds.
How many extra steps to their task do the PvEers have to engage in after and during their gank? Well first we die or live but usually die , then we type /pvp then we wait 5 minutes , then we start to PvE again and risk the same steps in repetition.
2 seconds of voluntary vs 5 minutes involuntary.