Because leaving home without one should be a crime against humanity.
I would like to report the condition of my KPA after the ungodly US backroads through the plains, fields and desert in a over packed trunk of a small family car. I grew concerned because everything inside my rack case was HOT to the touch and then when i plugged it in [after letting it come to room temp] i wasnt getting any power. I was fucking pissed! Immediately I started to panic. As luck would have it after trying 3 separate outlets I got that wonderful blue screen to fire up and my panic subside. Turns out the first 2 i had tried were wired in with the light switch of my suite.... LOL PHEW!! KPA A-OK! 
Gotta love that German engineering.
Happy end...