Thomas More isn't all that prone to emotion in Utopia: the mood of the novel is mostly informational and serious, with its author fixating on rhetoric rather than the trials and tribulations of fictional characters in his pursuit of a social critique. In this text, the characters are not developed in the more traditional sense, nor is the plot. Rather, the characters and their circumstances are a thinly-veiled scaffold for More's political arguments. The drama is in the complex interplay of More's rhetoric rather than in the emotional interplay between fictional characters. This more informational, argumentative (but emotionally flat) mood is augmented by the fact that More breaks the fourth wall and includes himself in his own story.
There is, furthermore, a certain idealism that infuses the mood of Utopia. More may not believe that a full Utopia is achievable—on this, his position remains ambiguous—but he does seem to advocate social change along the lines of the Utopian commonwealth. Consequently, the logical, informational aspects of the novel's mood are seasoned generously with hope. More's England may be rife with inequality, poverty, and corruption, but he has enabled himself and others to envision a better society. While More does not express this hopeful mood in outbursts of emotion in Utopia, it is nonetheless present and implicit in almost every argument and rhetorical claim.
