Thompson is just a shadow of its former self from years gone by as far as Luton is concerned. Just compare their present Gatwick operation to their Luton programme. Is it really that demand has plummeted from its Bedforshire base? Well they can't blame the likes of Easyjet who are big at Gatwick so there must be another reason. I think the business is there but Thomson are pushing passengers to Gatwick from the London area.
As for long haul from Stanted? There is hardly a passenger flight that needs the extra runway length that Stansted can offer over Luton so in that sense it is a failed airport as most of the long haul business uses Heathrow or Gatwick.