In Star Trek the Original Series, the different shirt colors are assigned to different fields in Starfleet. This is barring the pilot and first few episodes when everything was finding it’s equilibrium.
Security wears red shirts. So of course they’re the first to die. That’s their job is to protect the others. When the crew beams down somewhere it’s only normal to have security with them. So naturally they have the largest body count. They’d be really bad at their jobs if they always lived and yet captain after captain dies every week.
Surely every Star Trek fan has realized this by now so I have to assume that the red shirt jokes only come from non-trekkies.
And that’s why the red shirts die first.
I’m watching The Trouble with Tribbles right now. My daughter is playing with her new tribble, Sheldon. Hence the post.