You know the guy in the war movie who gets shot early on and takes two scenes to die? Kind of like the Star Trek extra wearing the red shirt—he means well, and everyone’s sad when he goes (well, sort of), but you know when you see him at the start of the show that he won’t be around at the end.
Same with old Zach Stortini. You know he has a good heart, and when you need a volunteer to run into the line of fire, or take the fall so Captain Kirk can somehow get laid—or get beat up by Owen Nolan—he’s the first to volunteer. But you know he won’t be around for very long.