Final answer:
Ellie was upset with Malú for wanting to cancel the Alterna-Fiesta because it was a significant event that celebrated diversity and individuality, key themes of the story.
Step-by-step explanation:
Ellie was mad about Malú wanting to cancel the Alterna-Fiesta because the event was important to them. The Alterna-Fiesta represented a celebration of diversity and individuality, two values that are pivotal within the context of the story. It was a chance for the characters to express themselves and celebrate their unique identities.
The idea of canceling such an event, which had the potential to bring people together and showcase alternative culture, was disappointing and upsetting to Ellie. This situation confronts themes of acceptance and the importance of community events in bringing people together.