The hanging of Maketū is important to learn about in highschool because it demonstrates a clear example of how the crown imposed power over Maori despite it being such a early time in the crowns development in NZ. This helps students get a greater understanding about how Maori customs had been replaced with queens law and how Maori have had disproportionate treatment - one example is that Maketū's defense lawyer was appointed an hour before the trial, and didn't even get to speak with Maketū. Learning about this case would broaden students understanding about the unfair outcomes for Māori resulting from colonization and its impacts. Furthermore, it would tie into similar topics students are learning at the time, which is significant as students would get far more depth and understanding of the initial topic focused on resulting in more information gained.
It is also good to be generally knowledgable about cases like this, not only for academic purpose but for a greater comprehension of our countries history and colonial outcomes. Insight is a powerful thing and can shape the way we see the world, good or bad. It is always valuable to get a grasp on incidents such as these for the sake of gaining awareness.