To say nothing of the fact that passengers loading their own luggage into the overhead bins significantly slows down the boarding process.
Everyone in the United States who carries on their whole set of luggage thinks they are saving themselves some time by not having to wait at baggage claim. But the social cost of everyone doing that is a delayed boarding process because there's not enough space on most planes for all that people will carry on. Then they have to gate check and the process slows down some more.
Kiwiflyer, why don't you fly UA or US and then board with *G to get your luggage on?