OK OK, let's be a bit more reasonable ...
I recognise your classification of IMCR holders. I don't know what I'm going to use it for myself, I haven't finished the course.
Mostly I'm doing the course to improve my skills. But the ability to not worry too much about how much cloud there is beneath me, and descend through it on the ILS at my home field if necessary, would widen the choice of days on which I could go for local joyrides. In a rented plane under the club's flying order book rules, which are rather stricter than the priviledges of the IMCR.
I don't know what evidenced case could be made for taking that away from us.
FWIW, at a few hours into the course I'm finding it hard work[#], and I don't expect to finish in 15 hours, and I would absolutely agree that I'm only going to learn how to do a subset of instrument flying not-very-well, and I can quite see that doing fifty hours or so is necessary to be taught the full range of skills to a reasonable level of comfort and accuracy. (It seems to me, for example, that to be comfortable tracking away from an NDB accurately at night with a vacuum failure and insufficient lighting to read the compass is worth a couple of hours on its own, in varying wind conditions, and obviously if you multiply that by everything that needs doing it comes to more than 15 hours.)
So, if the IMCR went, whilst I would regret its passing, I might decide to get some sort of IR by doing "the rest of" the training. What seems unreasonable is
(1) that the training already undertaken won't count
(2) having to pass exams in lots of stuff that isn't relevant to flying a 172 outside controlled airspace (which is all I would want to do with it).
Hence musing about potential "short cuts" which might avoid (1) and (2). Still doesn't seem unreasonable to me.
[#] Which is good. People like challenges from time to time.