This is a great viewpoint. Although none of us wants to be replaced unless it's by our own choice, we also typically have enough ego that we want to be remembered in a positive light. If someone else takes over for me and their job is terribly difficult because of the way I've done things, you can bet they will complain and let everyone know that I left a mess.

Hopefully most of you can agree to this - I absolutely love most of my customers, and I don't want to leave them in a bad situation if I leave my position. Therefore, my own "job security" aside, I do try to make sure that I am replaceable.