Originally Posted by jjglaze77
Perhaps time is required to check documentation? I mean, when traveling domestically, all ID checks are not left to the GAs boarding a flight. Internationally, showing the passport is still required. Perhaps they would like everyone there in case they have a last minute question about a visa, travel document, etc. It does take a little longer with the document checks to board a flight, but aside from that, I think it just has to do with the fact that you are crossing into another country that could assess DL a hefty fine if they board you without the proper docs.
Actually, US citizens only need to show their boarding passes when boarding even international flights out of JFK. Non-US citizens have their I-94 departure card attached to their boarding passes so the agent only has to make sure it's there but again, passports are not checked. The only flight I've seen departing JFK with more checks has been the JFK-SVO flight (not actually been on it) and the checks usually happen the moment you arrive at the gate, not when you actually board the plane.
I think they always post more conservative times for check-in and for showing up at the gate so that if all things are operating normally, they can start boarding earlier (usually 35-40 minutes before) and dispatch the flight earlier.