Plymspotter - Sorry but first came Westward Airways flying LGW/LHR/PLH/NQY/ISC - and probably others before but I am not THAT old - in any event first came the horse and cart so let's look ahead not back.
In my view, frequency ex NQY is very important to sustaining a service to London and you can't do that with a 130 seat aircraft, it would be better to have 6 flights a day on a 19 seat aircraft than one on a 130 seat, but of course you can't do that either to LGW as the slots / costs would prohibit it. So NQY is in a bit of a catch 22 situation.
In an ideal World there would be a little commuter airport next to Gatwick, like Redhill with an adjacent station serving Gatwick and central London and fees low enough to make it all economic.
If there was an easy answer it would have been found, there isn't - suggestions on the back of an envelope.....