> Changing airport is anathema to most sane people
It's not just about time or inconvenience. Nationals of Ghana can transit the UK airside (at the same airport) without needing a UK visa in most cases, but changing airports means they are more likely to need a UK visa (there are fewer exemptions).
Americans don't realize that a lot of other airports around the world let you connect to other international flights without having to pass through immigration and customs. The USA is really backwards in that respect.
...Which is amusingly because the US is less strict at immigration/customs than most other countries. Since it lacks any exit controls, there's no need to segregate the international departures section of the airport, which has the side effect of meaning you have to enter the US to get to your connecting flight.
It's not just about time or inconvenience. Nationals of Ghana can transit the UK airside (at the same airport) without needing a UK visa in most cases, but changing airports means they are more likely to need a UK visa (there are fewer exemptions).