Nothing positive can emerge from hatred. Conversely, we only hurt ourselves by allowing animosity to gnaw away at our emotions. True, Hashem uses an evil person to carry out evil. Nevertheless, it is Hashem's will that we are criticizing. Second, for our own emotional and physical well-being, it is much healthier to ignore the evil around us and to go on living.
Hatred only makes matters worse, granting more success to our detractors.
They had sold their brother into slavery, and Hashem was delivering their retribution. Indeed, in the Talmud Tannis 9a Chazal allude to this. A fool makes a mistake and then complains about the punishment he receives from the Almighty. Likewise, the brothers had sold Yosef and now they were unwilling to accept the consequences of their actions. After all is said and done, the brothers should not have sold Yosef.