Shakespeare simplifies the conflicts to match the adolescent mindset. Romeo and Juliet see their relationship and the world in terms of good and bad, love and hate. We are reminded of this many times through the play.
Romeo: O me! What fray was here?
Yet tell me not, for I have heard it all.
Here's much to do with hate, but more with love.
Why then, O brawling love, O loving hate.
Juliet: My only love sprung from my only hate!
Too early seen unknown, and known too late!
Prodigious birth of love it is to me
That I must love a loathèd enemy.