I can certainly confirm that Norwich has far less movements that either White Waltham or Wycombe Air Park and I suspect less even than Seething, in absolute numbers. But in terms of heavy traffic, Norwich has a fraction of the movements of either Biggin Hill or Farnborough and neither of these fields feel it necessary to requisition a huge chunk of airspace for their exclusive control.
The argument to say that if Norwich were to get a huge swathe of controlled airspace, would result in more commercial traffic is specious; akin to arguing that if you were to build another hospital, people would have more accidents in order to use the capacity.
What is clear from the application is that Norwich has a problem communicating effectively with it's millitary neighbours over the shared use of airspace and this should be something that an effective management could deal with by a telephone call or two, as opposed to the imposition of a chunk of airspace the size of Gatwick's zone. This is a management failure
Honestly, this is all reminiscent of the Argyll and Bute Council/Jackson space-port debacle, up in the western Isles of Scotland; the only losers will ultimately be the taxpayers footing the bill for this silliness and the GA community who will yet again be effectively excluded from another chunk of airspace.
Of course I accept that on paper that space will be available for transit, but anyone who has to transit Doncaster/Solent/Durham Tees's zones on a regular basis, will know that in practice, such permission is with-held between 25 and 50% of the time.