I agree, I can't ever imagine folding pocket Kings pre-flop however it depends on your portrait of your opponents. If I had an extremely large chip-stack there were two significant re-raises from very tight players, I might just let them fight it out.
I think if you start folding the second best pre-flop hand you're losing out in the long-run.
What I find more difficult is holding pocket kings and seeing an Ace on the flop after someone has called. Squeaky bum time.