So on the one hand we have an airport that people prefer to fly into that will be connected to Central London by a brand new Crossrail link, the west with a new rail connection and connected to the midlands and north by a 'just built' state of the art high speed rail link.
And then we have Gatwick with its recently voted, worst rail station in the UK.
Personally I think we should expand them both but only one will be a hub with easy road & rail access to large parts of the country.