The motivation of the perpetrator is a substantial factor in determining the mens rea of the actor. It is manifestly unfair to punish one who acts from desperation or the heat of passion the same as one who acts from greed, malice, or other sinister motives. Homicide is a prime example. Murder by definition is the unlawful killing of a human being by another human being with malice aforethought. The very definition implies that the crime was committed after calm reflection; literally "in cold blood." Killings committed in the heat of passion or as the result of gross negligence are still crimes, but do not have the same degree of intent as a homicide committed with malice aforethought.
Both hate and revenge are heinous; and it is difficult to imagine that one is less culpable than the other. Both imply a degree of reflection and the opportunity to reflect on one's actions. For that reason, they are indistinguishable in terms of mens rea.