Elphaba’s refusal to take on the title of Eminent Thropp matters because it shows she has no interest in ruling or controlling others, even if she might think she can do the job better than Nessa. Nessa, on the other hand, has justified cruelty against Munchkinlanders and Animals by convincing herself she’s acting righteously. Frex’s confession about Turtle Heart, meanwhile, is his way of reminding Elphaba that personal choices have consequences. He warns that one’s family, faith, and politics are all entangled, and that turning away from leadership—like she did when she went underground—might also mean losing the chance to stop things from getting worse.