Having read the original article again, I am staggered at the low numbers participating. 47 flew the approaches; 26 filled in the feedback form.
I also gather that some individuals have flown multiple approaches, so the # of pilots involved is substantially smaller than the above numbers.
Why so few?
It's been apparent for some time (I started flying 5-6 years ago, under JAA) that the number of JAA IRs issued in the UK to genuine non-commercial pilots has been running in single figures per year. This is seen on the CAA license issue website.
However, there is a significant group, comprising mostly of older pilots (I am c. 50 and I am talking people mostly older than myself) which goes back some decades to when the IR was a bit easier. Some have also flown commercially. As a very rough guess, I would put their numbers at about 50-100 in the UK.
So what has happened to all these CAA/JAA IR holders?
Are they really going to the trouble of renewing their IR every year, but not actually flying? If so, how do they pass their checkrides, with zero currency??? You would never pass an FAA IPC if you did that.
Maybe it's because most of them don't read pilot forums on the internet. This is very likely. We also know that most experienced pilots don't hang around any flying school/club. If they fly, they fly alone, outside the system. I don't know how many of them read the UK aviation mags but I don't read them myself; they contain little of relevance to anybody past the basic PPL stage and even less of relevance to owners of something more advanced than a PA28.
Did the CAA promote the GPS trial by mailing known IMCR/IR holders? I bet not.