'Why' can be used at the start of a comment as an interjection to show surprise. It is not being used as a question word. Some people consider 'hell' to be an offensive word (a curse word). She says 'war' should be a curse word because war is a horrible and offensive thing in reality so the word should be considered offensive.

wtf?哦利谢！OMG

Many speakers (at least in the US) use different pronunciations of this word, depending on the meaning. If is an interjection it is pronounced wai, but if it is a question word it is pronounced hwai.