In Hurston's novel, sexuality is depicted as a rich, natural, and affirmative aspect of life. It's something that her heroine, Janie, enjoys when she's a young woman first learning about her desires, in the context of spring and blooming pear trees, and something that she enjoys when she is a "handsome" older woman who refuses to play the widow for the rest of her life after her husband, Joe Starks, dies. Knowing that she hasn't experienced the love that she really wanted with Joe, who treated her more as an object to be won than as an equal, she finds fulfillment with Tea Cake, who is younger, poor, and itinerant. He is the opposite of Joe, but in being open to a life with him, Janie discovers aspects of herself that she might not have known had she remained in Eatonville as "the mayor's widow." Though she loses Tea Cake, Janie remains grateful for what they shared together. Her relationships with men have enriched her life because of what they have taught her about herself.
Zora Neale Hurston published Their Eyes Were Watching God in 1937, when Black literature was mainly defined by the protest novel. At the time, Richard Wright was one of the best-known Black writers and he loathed Hurston's novel for what he considered to be its "facile sensuality." Wright, like most Black writers at the time, who were male, was more interested in frustrated sexuality and the emasculation of black men, which shows up within the protagonist of his best-known novel, Native Son, which was published in 1940.
Sexuality has everything to do with pleasure and nothing to do with brutality in Hurston's novel. Though there is a scene in which Tea Cake strikes Janie for befriending Mrs. Turner, who thinks that Tea Cake isn't good enough for Janie because he is darker-skinned, this is a moment in which Tea Cake exhibits weakness due to internalized racism. He incorrectly fears that Janie may agree with Mrs. Turner and, indeed, leave him for Mrs. Turner's son. Wright may have overlooked this scene, in which Hurston explores how racism threatens to destroy love.
In his description of the novel as "facile," he also must have overlooked how Janie's emerging sexuality arouses fear in her grandmother, who worries that Janie will become a loose woman like her mother, or will be impregnated and abandoned. These concerns are certainly as complex as any that Wright's male protagonists would have faced.
Unlike Wright, Hurston wasn't particularly interested in using sexuality as part of an overt political statement. She also wasn't interested in demonstrating "the Black condition" to white readers, which was the concern of Wright and many other Black writers since the Harlem Renaissance. She talks about this in greater length in her personal essay, "How It Feels to be Colored Me." This lack of concern for white readers, as well as the unusual focus on a black female protagonist who was neither tragic nor defined by men, but by experience, made Hurston an outlier in her era. Her unique perspective and disregard for the heavy-handed conventions of protest literature are also reasons why we continue to read her novel.