Ding, ding, ding... give the man his prize - exactly, and any halfway competent strategist could have predicted this would happen, oh wait, they did, that's why we have signs saying that you can't stop your car outside the terminal entrance, and other such precautions that were put in place because of this very threat. The fact that this was a target rich environment and that al Qaeda, and then later on ISIS, has had messages intercepted of plans for such an attack will not stop politicians from trying to downplay the reality. Heck al Qaeda hasn't given up on doing themselves, so ISIS isn't the only one we have to be concerned with doing such an act.
ISIS is expanding to Libya, eastern Egypt, Syria, Iraq, Yemen, and other geographical areas... and their supposedly getting desperate because they've been kicked out of Fallujah and parts of Ramadi... again? It's not like this is the first time, and it's not like they can't retake either if they really want to.
We'll see.