The same way you guys say hank's not blood how can you not understand hank's POV?
He nearly got killed because of the shit that Walt did. Many people died because of the shit Walt did. He feels he's doing right by his family - his wife, by trying to take down Walt.
Why should he be loyal to Walt? Way has Walt done for him besides nearly get his ass killed. He knows the danger that is around the corner. Remember, the quality of meth is dropping. And I think some VERY powerful people will want that number to be much higher....