Why would anyone think he would take any responsibility, aka "The buck stops here"?
Much easier to point fingers and say, "You're fired".
My opinion I think there was little inherently wrong or illegal with the executive order itself, but the way it was implemented, with no communication and time for the airlines, airports or travelers to prepare - was boneheaded. And the worse part, he goes on TV the next day and say it's working beautifully at the airports. It was a free gift to the liberal media.