I believe it was because of the raw violence and just oddity that was seen in the book, back then it was not common to go see a movie that had so much killing, much less read a book where you get chosen and stoned to death. That age was a little more innocent. Hope this helps.
In an argument, you're trying to convince the reader to agree with you. A show of emotion or being emotional shows that you believe in and/or passionate about your topic.
