Ernest Lanc's
I am willing to pay that bit more for convenience, and so IMO: are others.
SEN has it's appeal due to it's ease of use.
I know where you are coming from as I pay a premium to fly IT from Luton when I can save a fortune flying from Gatwick. Locals will always pay a premium to fly from their local airport and maybe Londoners will for the convenience of using Southend but the passenger loads might now be telling a different story.
I have no idea how true this story is as I might have been fed duff information.