Alternative Character Interpretation: Was Erin a good-natured young woman who, despite making mistakes, had the best intentions at heart and is a genuinely likeable person or was she an idiot that had to have things her way and got everyone in the movie killed?
The original script had her pregnant, which gave her motivation, but is that justification?
Morgan comes off a little better though, thanks to performing a Heroic Sacrifice to save Erin.
Catharsis Factor: After watching our main characters suffer and die for a very grueling 90 minutes, its extremely satisfying to watch Erin viciously run over Sheriff Hoyt multiple times with his own car.
Also Erin chopping off Leatherfaces arm with a cleaver.
Plus, the horrific physical and mental torture he goes through such as having a bottle smashed in his face adds a lot of sympathy.
Nightmare Fuel: The opening and ending scene with the police and camera man going into the basement of the Hewlett household only to then be attacked by Leatherface. The black and white aesthetic does not help.
Narm: Having Erin run around in a wet t-shirt while trying to flee from Leatherface makes the whole scene come off as the opening of the first Scary Movie rather than a suspenseful fight or flight situation. What a weird place to incorporate fanservice.
What an Idiot!: Leatherface drops his chainsaw right in front of Erin. She sits on the ground screaming and doing nothing productive, leading to her friend's death. Way to go, moron.
The Woobie: Pepper. She's genuinely a nice, likeable person who only wanted to help the hitchhiker and found herself being unfairly punished for it.
Andy too. He may not be fond of helping the hitchhiker, but he's clearly very loyal and protective of his friends ( performing a Heroic Sacrifice to save Erin, even) and suffers the worst fate of the film, even worse than Morgan.