For two reasons:
A. He went to Congress to explain why he would not recommend a prosecution and promised them "updates". He doesn't work for Congress. He works for the Attorney General of the United States. If they have any questions, they should ask the Attorney General.
B. He interfered with the presidential election days before it took place. The policy of 60 days that the DOJ has in place is there for a reason and has never been fked with.
The guy does not realize the weight of his position and the responsibilities of his job to his SUPERIORS.
Hillary or Obama, one or the other SHOULD dump him. Ask for his resignation, PRONTO.