What about the reluctance of many, many pilots out there to fitting radios, transponders or making use of the ATC services that are available?
I am not sure if you fly, Roffa, but the problem is this:
If you are flying VFR, or the non-Eurocontrol OCAS IFR which is common in UK Class G, then you have to have
Plan A - the route you would like, and
Plan B - the (longer) route you fly if you don't get the transit(s) for A)
So everybody (with a brain) has to have a plan based on not getting a transit - because sometimes they don't get it. And if you have that plan, loaded into your GPS, why not save yourself the extra workload of doing the radio and just fly Plan B, non-radio? My radio is actually pretty good; after nearly 800hrs it's better than many I hear, yet I prefer to go around e.g. LCY airspace quietly because it's less work for me. I might call up Southend instead but they don't have SSR - presumably because they don't want to pay the going rate for the feed.
So one can't blame pilots for not talking to ATC. One can get transits but it's sporadic, I guess depending a lot on the controller on duty, and after a while most people don't bother to ask.
Thames Radar are the losers here because they might be vectoring traffic to Biggin's ILS in Class G, yet the inability to provide a universal service to Class G in their area means that they will have nontransponding contacts in the same place. They probably get away with it because when the weather is OVC010 or worse the sky is relatively devoid of GA and there won't be many non-C contacts in the ALKIN area to start with.
Biggin pay for the Thames Radar service, I gather.
Don't jump to conclusions when you don't really know the full story.
I doubt many private pilots know even a bit of the story. But here's your chance to set the record straight. Why not tell us all about it?