Many stories feel flat if the antagonist has simplistic or one-dimensional desires.
In basically all of the James Bond movies, the villains want revenge and/or world domination.
In contrast, in Worm [1] you spend some time with the antagonists (and a lot of side characters), and get a much better appreciation of their feelings and motivations. Sometimes you even feel sympathy for very messed-up characters to the degree that it creeps you out. (Fun fact: there's even a chapter from the perspective of a dog. Brilliant! :D)