it's so big that there's even a themed account for it

the comic by ctrl alt delete has been made fun of so much through parody comics (like this one), and also so well known that the bars/legos/whatever correlate to the positions of the characters and the panels.

But why? It's so depressing

It's because Ctrl+Alt+Del has always been a comedic webcomic about video games and stuff and suddenly they toss out a dark and poorly execution subplot about the main character's fiancee having a miscarriage out of left field.

It's memetic because it's so bad it's funny.

first time I saw it I was confused as well, but the bars represent the people as shown by this overlay