I understand the thought for it and I mostly agree with the sentiment, but its far too long. It would still be effective at 45 seconds or something. I believe this is having a bigger negative impact on the pking scene than you guys realize.
Yesterday anytime i went to switch chars for pking i was hit with the 120 seconds(in total i probably had to wait over 10 mins). By the time i go in, the pking is over or the person is no where to be found. I understand for pjing, or getting a guy low who killed another of your chars, but that can be done with a much shorter timer.