When there is a guest star that appears now and then that you like.

It's always the guest stars that we like that gets sacrificed.

List of guest starts that I liked that got killed:

Kevin Trant - Supernatural
Charlie Bradburry - Supernatural
Janet Frasier - Stargate Sg1
Mike Frank - NCIS
Jemada Thapa (Gurkha member) - NCIS Los Angeles
Jenny Sheppard - NCIS
Bobby Singer - Supernatural

The list goes on but I'm too lazy to write down them all.