Some person in the state department several steps below Barack Obama because it’s not the job of the president to determine the security needs for individual embassies and consulates. Believe it or not, the president doesn’t do every job in the federal government.
Which is why Barack Obama wasn’t over in Libya personally hunting down terrorists. That’s not his job.
Anyone who’s ever been the boss of anything knows you delegate a lot of stuff you are ultimately responsible for to other people to carry out.