What bothers Holden about Mercutio's death in Romeo and Juliet?
He seems to take a liking to Mercutio than to Romeo, I never read Romeo and Juliet before, so I wouldn't understand why Holden perfer one over the other.
Holden says this when he is talking to the nuns in Chapter 15.
As for Mercutio and why Holden would like him, Mercutio is, as Holden says, very smart and funny in the play. He has a very good wit and is a pleasant guy.
Holden feels sorry for him because he gets killed when it's not really his fault. Much of the problem in the play is caused by Romeo and Juliet falling in love with each other even though their families hate each other. That's why when they die, Holden says it is their own fault. But Mercutio's death really is not his own fault. He only gets in a fight because Tybalt is mad at Romeo for hanging around Tybalt's cousin Juliet.
So the point is that Mercutio is minding his own business and gets killed for something that Romeo did.
Of all the characters in William Shakespeare’s Tragedy of Romeo and Juliet, it seems very likely that Salinger’s Catcher in the Rye character Holden Caulfield would identify most with Mercutio. This is probably why he is bothered by his death.
Like Mercutio, Holden is not tied up in a relationship throughout the play, as Romeo is. Mercutio is possibly the most likable character in the play. Although he doesn’t last long, his speaking parts are filled with humor—which is another way in which he resembles Holden. Holden’s first person narration is intended to inform us, but also to be entertaining, and in this vein he makes a lot of surprising statements. So does Mercutio. Some of Mercutio’s statements are of a sexual nature, such as:
Now will he [referring to Romeo] sit under a medlar tree
And wish his mistress were that kind of fruit
As maids call medlars when they laugh alone.
The humor here is in the word “medlar,” which is a kind of fruit, but also sometimes used to refer to female sexuality.
Holden makes a lot of sexual references in the book, and it’s obvious that he has sex on his mind at times. He probably finds Mercutio’s jokes funny because he seems to be thinking the same way.
Finally, as the first post above noted, Mercutio is killed through no fault of his own. Holden sees himself the same way. His problems in prep school, and he has had plenty, seem to him to always be somebody else’s fault. It’s the “phonies” who cause his problems, not his own impetuous actions.