Even though Agnes is our narrator, we don't get a very clear picture of her as an individual. We don't even really know what she looks like. The closest we get to a physical description is when she compares herself to her best friend Ursula-Marie, whose blue braids she covets: "If my mother hadn't expressly forbidden it, my hair would have been blue too. As it was, I had to make do with the six braids, which weren't particularly impressive given my fine, wispy hair, but at least it was something."
Later, she gives us a tiny glimpse of her wardrobe, again as compared to Ursula-Marie: "If my mom hadn't kept on sabotaging it all by buying those garish clothes for me, I would have worn only black too. As it was, I had to make do with one pair of black pants, two black T-shirts with funny slogans in English, and one black woolen undershirt."
The gist? Agnes has trouble defining herself by herself. She's always comparing herself to others, and seeing how she stacks up. That makes her both a typical pre-teen, and easy prey for Pierre's rather judgmental take on middle school life.
Teller makes Agnes nondescript for a reason: her place in the allegory is to be the voice of the group. She speaks for all those inauthentic folks—so much so, in fact, that she uses the pronouns "we" and "our" more often than "I" or "my."
Take, for example, her delight when Frederik demands Lady William's diary after giving up the Dannebrog. She tells us that in asking for the diary, "he rose significantly in our esteem," although, in forgetting to ask for the key, he "[fell] just as quickly… as he had risen." She never indicates how she knows what the rest of the group felt, but she feels comfortable speaking for them.
Anyone who is truly authentic, in the existentialist sense of the word, looks at the world through the lens of her own experience. In other words, everyone's different, and sees the world differently. Agnes, though? Not so much. Agnes experiences the world through the lens of the group. What they say goes, no matter how nutso.
She's so much a part of the 7A Borg that she goes along with robbing Emil Jensen's grave and dutifully stays home the night her friend Sofie is being raped. The day Sofie loses her "innocence," Agnes sits silently at school like the rest of her classmates, saying, "No one else dared say anything either for thinking about what was going to happen to Sofie, and it was almost worse than when we were making trouble." What she doesn't realize is that in remaining silent, she's making the worst possible kind of trouble: she's condemning Sofie to rape rather than saving her.
The short answer: yes. It's easy to see that fear makes Agnes do what she does, and we can all relate to that. She's afraid of Pierre Anthon being right, and really, who wouldn't be? It's terrifying to imagine that nothing matters. The minute Pierre Anthon walks out of the classroom, Agnes says, "Pierre Anthon left the door ajar like a grinning abyss that would swallow me up into the outside with him if only I let myself go" (2.12). Yikes.
Plus we can't forget that Agnes is, in many ways, a typical 7th grade girl. She wants to be a fashion designer, she loves her new shoes and her best friend, and she wants to grow up, fall in love, and get married. And when all hell breaks loose at the end of the book, and the rest of her classmates are going nuts right alongside Sofie, Agnes is the one who runs to get Pierre Anthon out of the tree in the hope of saving the day. Finally, she breaks away from the group and does something on her own.
So it's not that she's unlikable; she's just not authentic (yet). The girl who forced Gerda to give up her hamster is taking a stand against the cruelty of her peers when she says to Pierre Anthon, "They've all gone berserk. You have to come" (23.33). Finally, she uses "they" instead of "we," and it's because she wants to save Sofie. She's showing the compassion for other people we thought she had buried beneath the heap of meaning.