SS, I'm very sorry you have lost friends in this way. I understand that there have been very few accidents involving IMCR pilots in IMC, so I think you are unfortunate (to put it mildly) to know of three.
The justification given above of using a rating to fly into what are basically icing conditions in a single-engine aircraft, shooting an ILS at the end to have coffee with friends is quite frankly ludicrous.
I agree, given you said "into what are basically icing conditions". Not a good idea.
...any rating that allows someone not fully trained to fly in instrument conditions in an aircraft not fully equipped for such is something that should be anathema...
I don't have the knowledge to dispute what you say, but presumably the CAA think the IMCR training is sufficient? As I say, I understood that the accident record is pretty good. As a proportion of PPLs, IMCRs are said (I don't have the source) to have a lower rate of accidents in IMC than non-IMCR rated PPLs.