why there is no need be not necessary
Why do you persist in blaming yourself for what happened?
你何必为已发生的事没完没了地自责?
—— 给力词典精选Why do you burden yourself with your sister´s dog?
你何必自找麻烦为你姐姐的狗所累 呢 ?
—— 给力词典精选Why should you work so hard for these people?
你何必替这种人卖力?
—— 给力词典精选We are all good friends ; why stand on ceremony?
都是自己人, 何必客气 呢 ?
—— 给力词典精选Never mind such trifles.
区区小事,何必介意。
—— 给力词典精选