I would be Emo too, if I had to go into battle wearing armor with that many gaps!
He's not wearing it. It grew out of his bones.
Movie props designers and comic book artists base their designs on what they think looks cool rather than what is practical or realistic. I guess that can be justified considering their job is to provide something impressive if not visually pleasing. However, a lot of their works don't stand up to scrutiny.
Taking a second look at Azog's armor made me wonder if the designer took his or her ideas from the Witchblade comics. But Azog will never look anywhere as good as Sara Pezzini.