Why is Romeo to blame for his and his lover's death? What are some examples and analyses of his impulsiveness, impatience, and irresponsibility?

Romeo is indeed a rash young man. While pining over Rosaline, he falls in love with Juliet at first sight and soon agrees to marry her. This shocks Friar Laurence: “Is Rosaline, whom thou didst love so dear, / So soon forsaken?” Romeo’s overwhelming passion is matched by Juliet’s, who proclaims that their romance is “too rash, too unadvised, too sudden; / Too like the lightning.” Certainly, if Romeo had not gone to the Capulet...

Romeo is indeed a rash young man. While pining over Rosaline, he falls in love with Juliet at first sight and soon agrees to marry her. This shocks Friar Laurence: “Is Rosaline, whom thou didst love so dear, / So soon forsaken?” Romeo’s overwhelming passion is matched by Juliet’s, who proclaims that their romance is “too rash, too unadvised, too sudden; / Too like the lightning.” Certainly, if Romeo had not gone to the Capulet party to spy on Rosaline in the first place, he never would have met and fallen for Juliet.

Romeo also kills Tybalt, Juliet’s cousin, after Tybalt slays Mercutio. Romeo tries to speak kindly to Tybalt but, in his grief, attacks and murders him. He even blames Juliet for his initial temperance:

… O sweet Juliet,
Thy beauty hath made me effeminate
And in my temper soften'd valour's steel!

Romeo reacts violently to his subsequent banishment, claiming to prefer death to such a fate: “There is no world without Verona walls, / But purgatory, torture, hell itself.” He wails and attempts to kill himself. The friar halts his sword, only delaying his inevitable death.

As soon as Romeo hears of Juliet’s death, he decides to die. Juliet, however, had only feigned death. If Romeo had waited and learned Juliet was still alive, they could have been together. Instead, he rushes to her grave and fights with Paris, Juliet’s fiancé, killing him. Romeo then drinks poison and dies next to Juliet: “Thus with a kiss I die.” When Juliet awakens, she also takes her life. In the end, the tragedy is by no means Romeo’s fault alone, but his haste plays a key role in the play’s unfortunate conclusion.