( Annoying af trope ) When the good guys possess perfect defensive position/advantages that was completely ruined by someone's sheer stupidity, pettiness, or selfishness

[u/Routine_Phase_8980]

I understand that these scenes must happen in order for the plot to continue but they still make me angry till today whenever I think about them because of how easy it could've been avoided. I doesn't mean these scenes are necessarily bad written, just hella hard to watch.

The Jerusalem Wall / The Singing Crowd (World War Z): Israel literally anticipated the zombie apocalypse and built a flawless, massive wall that kept everyone 100% safe. It was the ultimate safe haven. But then people inside started celebrating and singing on a microphone so loudly that it triggered a zombie pyramid, they didn't even stop until the first zombies started coming through. They have less survival instinct than an amoeba.

Ephialtes (300): The Spartans had the perfect phalanx formation at the Hot Gates. They were slaughtering the Persian army with minimal casualties and could have held them off for so much longer. Then this guy gets his feelings hurt because he can't lift a shield, throws a tantrum, and tells Xerxes about the secret goat path.

Grandma Jong-gil (Train to Busan): The survivors fought through hell and literal waves of infected to secure a safe train car. Sure, the crowd inside was selfish for locking them out at first, but everyone was finally safe inside. Then this grandma, fueled by grief and spite over her sister, decides to open the door and let the infected flood the entire car, killing everyone.

[u/ZeitgeistGlee]

Ephialtes (300): The Spartans had the perfect phalanx formation at the Hot Gates. They were slaughtering the Persian army with minimal casualties and could have held them off for so much longer. Then this guy gets his feelings hurt because he can't lift a shield, throws a tantrum, and tells Xerxes about the secret goat path.

I never understood why Leonidas didn't do the very obvious thing and just stick Ephialtes at the very end/edge of the shield wall. The guy next to him wouldn't have had any more/less protection than before and Ephialtes would get to live out his dream/uphold his promise to be a Spartan warrior before probably dying early in the battle after which he'd be out of the way. There were literally no downsides.

[u/Arvendetta → u/ZeitgeistGlee]

Well he didnt fit into their hot guy calendar aesthetic

[u/angikatlo → u/Arvendetta]

Well, not really. It was because he didn’t share their particular preferences for partners.

[u/ZeitgeistGlee → u/Arvendetta]

Man I can't believe the people who leave their infants outside to weed out the "weaklings" would bodyshame someone.

[u/twisted4ever → u/ZeitgeistGlee]

I think he should have employed ephialtes as a finisher (As they go forward in the phalanx a handful of soldiers check for surviving enemies on the floor and finish them with a spear so they dont get up and backstab the front line. Every phalanx in the movie you can see them.

[u/Talanic → u/twisted4ever]

Honestly Leonidas being an elitist who sees no use for anyone who doesn't fit in is fairly accurate. 

[u/IamScottGable → u/ZeitgeistGlee]

The other side of it was do they think Xerxyis didn't send people to look for a way around?