In the end, and i think this is easy to forget, some people actually left the island, on a plane. And half of them didn't arrive on 815. :/
I think there should have been way more losties leaving, alive, including extras from the first four seasons.
Ugh it didn't really seem like Jack died for anything, they really lost the climax. The End was awesome until the Jack/Locke fight, well when Kate shot him. After that it was all downhill and anticlimactic and mostly disappointing.