TV Industry jargon: When an actor leaves a show, and the character they played is then Killed Off for Real, they've been McLeaned. As for why a TV show might do this rather than simply putting the character on a bus, there are generally two reasons: 1. The odds of the actor returning to the show are next to nil, and killing them off gives the writers a chance to inject the series with some drama. If the actor has not simply left the show, but life altogether, then this becomes The Character Died with Him, and the way the character is written out is generally very respectful.