and presumably are therefore in receipt of a radar service and would only let down using a proper published procedure. If not, what the f*** are they doing?
Transitting Class G, around the Heathrow, City, Gatwick, Luton and Stansted CTRs, that's what they are doing.
You would have to ask the individual pilots why some don't obtain a service if that's what they do, especially now that Farnborough LARS has thankfully been increased in capability. For years before there was no cover available north of LHR.
However, obviously there is sometimes
no need to carry out an IMC letdown if suitable VMC weather exists at their destination.
FiFB, Yes, that area around Kidlington is a difficult one to safely transit, with Oxford IFR departures not always speaking to Brize Radar.