Well, yeah—it’s not like the four main characters are the only jerks, surrounded by sympathetic, innocent victims of their jerkishness.
ftg said the characters are like children. There may be an element of truth to that, but overall, I disagree. The characters’ behavior is guided, when it’s guided by anything beyond self-absorption, by manners without morals or heart. Their decisions on how to act are based on what’s “done” vs. “not done,” not on what’s “good” vs. “bad” nor on any love, compassion, or empathy. This is not, in general, true of children.