As opposed to the hulking monstrous giant spider that she *should* be…
Look, if anyone has actually even the slightest of interest in J.R.R. Tolkien’s Lord of the Rings, and Middle-Earth mythos, then they know that Shelob was a giant spider. She was a giant spider, and she was pure evil, and in fact she is related to the original source of all evil in Middle-Earth (her mother Ungoliant once served Melkor, who became Morgoth, the original Dark Lord).
So when you turn her into a woman who is helping you along on your quest… well, you’re taking a lot of liberties with the series’ lore, enough that your story has become glorified fan-fiction at that point. Monolith’s creative vice president Michael de Plater has decided to calm Tolkien nerds like I, by trying to justify the reasoning for making a giant spider into a woman.
“Why would you take the form of a spider? Because they’re terrifying. It really is to provoke fear, there’s a psychological dimension to that, and the other thing with Ungoliant and the spirit of darkness is this line that she hates light but she craves it, and so Celebrimbor and the new ring also represent this new thing that she has a love / hate relationship with,” he said to Eurogamer, adding that she needs to communicate, and a human form is best for that.
… this does not make it even the slightest bit better. Guys, you could have just made up a character if you needed one to help Talion so badly. This is just… walking all over the lore.