I absolutely hate it. It makes my blood boil when someone says "whatever" when I have them backed into a corner during an argument. To me, it seems like they're putting their fingers in their ears and going "lalalalala". To me, it's like a slap in the face, like they're saying "you're right, but I'm still "more right", like they're saying "you're right, but I'm not going to let you win the argument".