Do the characters get a bit more complex than “humans killed ppl I loved so now I’m going to plot to end all human life”? Because it was really hard to suspend

Do the characters get a bit more complex than “humans killed ppl I loved so now I’m going to plot to end all human life”? Because it was really hard to suspend my disbelief on that one. People just don’t behave in unidimensional ways like that. And they forget trauma, fall in love, gain contrary motivations. Humans are complex creatures.