>>92188520I think because it's a world devoid of love and affection, that constantly shits on the main characters, so people kinda empathize and want to see them get a happy ending.
Also, the characters have aspects of their personalities that are quite similar so they can mesh pretty well, with Zim and Gaz sharing a loathing of humanity and a strong drive to get what they want, and Dib and Tak both seeking approval from others (Dib from his father/humanity, and Tak from the tallest).
But that's just what I've taken away from all this.
