As far as I understand it, it's only mandatory if you want to go through the terminal building.
If you want make arrangements to visit one of the resident G/A or training operators, avoiding the nause of security and extra fees, no handling is required.
Unfortunately the above (which works everywhere in Europe, not just the UK) may require subterfuge. Some airports are getting wise to it; I was closely questioned by Bournemouth tower last year as to whether I actually did business at the establishment where I was parking.
At Norwich, people go via a certain school (don't know which) but that will be OK only for the locals who have the contacts. However this then involves parking on grass, liberally covered in pebbles and with a few potholes. I had some regular business there a few years ago and narrowly avoided prop strikes only by walking the route first.
It's doubly stupid because Norwich has a vast army of security staff whose time is wasted confiscating toothpaste from GA pilots. What is their average salary? I am sure it is well above NMW.
As has already been said.....if the runway isn't being used by your friendly Ryan or Easy, then all facilities are under utilised. What harm does 'G-XX, one orbit left for spacing from the inbound jet traffic" do. I'd rather have £10 from a PA-28 than nothing at all.
In communist countries, people would be locked away for that kind of progressive thinking
Can't do that in the UK either. But yes it's obvious.
p.s. where is EGNV? I can't be bothered to go and look it up.