Romeo and Juliet illustrate the nature of love because even thought Juliet wasn't really dead, Romeo still committed suicide over the thought of her being gone, she threw away her whole family to be with Romeo. But basically they were just stupid teenagers with love and lust that went horribly wrong
You could blame it on their families, fate, Friar, or Romeo and Juliet The families didn't help by not letting them be together, Frair helped with most of the deaths suggesting