The comparison with the USA, with its very different aviation scene, and its IFR privileges which are well integrated into its culture at all levels from low end GA to ATP level and whose achievability or syllabus are practically never even discussed let alone questioned anywhere on the vast U.S. aviation scene, makes for a funny and apparently provocative one-liner question on Pprune (and which really should thus have been posted on Flyer instead) but it doesn't help to work out a way to convince a number of traditional European aviation professionals that the skill set required to fly in IMC is nothing like the gold standard which they have spent their lives guarding.
A lot of it is down to personal experience. The people who object to any form of reduced-content IR (let's forget what one should call it for now) tend to be people who don't actually fly GA IFR. And many don't fly at all.
Even on pprune, it's dead easy to spot those who don't fly, from the stuff they write (or, more accurately, don't write).
The same is probably true for airline pilot bodies and airline pilot unions. There may be some active pilots among them but there are a couple of reasons why these people will have little or no GA IFR experience.
Firstly, if an ATP does fly for leisure, the last kind of flying he will be doing will be IFR. Ask any syndicate / timeshare setup how many serving ATPs they have as members. Most ATPs are a bit sick of IFR. For leisure, they fly rag and tube types. 100.000% VFR and on CAVOK days.
Secondly, GA of any sort and particularly IFR GA, is pretty thin in most of Europe. The UK is busy, Germany less so, France a lot less so, and the rest of Europe has relatively hardly any activity. By the time you get down to Greece you are looking at (of the order of) 200 GA planes - about 1% of the UK fleet.
This is why, as I have written many times, if you fly from say UK to Croatia, you might see 10 planes on a short leg in the UK but by the time you are in France the airspace is empty and then it gets even more empty. By the time you reach the Alps there is almost nobody "GA" on the radio. There are probably a few thousand IFR diehards zooming around Europe but even if each of them did 200hrs/year you would rarely meet one. Getting the full IR has been just too hard for too long.
So, taking Europe as a whole, there is going to be very very very little experience of GA touring among the people engaged in aviation professionally.
So it's no wonder that they don't understand.
And remember this is the same problem for both the "Euro IMC" and any reduced-content IR. Both of these initiatives are well stuck as a result. I wouldn't like to guess which is more stuck. Obviously the degree to which the IR is stuck depends on how much of the gold plating you want to take off - a recent 25% strip-off took ages and still got stuck. A "Euro IMC" is well stuck at the very start because it goes to the heart of the matter right away.
One could have a fun strategy debate which of the two is best worked on to un-stick it, but one thing is certain:
A "Euro IMC" would get picked up by a large % of pilots around Europe. Anecdotal evidence suggests the French and German PPLs would absolutely love it; especially German (and German-speaking) ones who do a lot more touring than the French. Whereas a "reduced IR", say 50% reduced ground school, would still be starting as an "IR", be taught by the professional schools, be examined by the professional pilot examiners, be fully ICAO and require the full JAA medical, and is never going to have much of a take-up. The yardstick for the likely take-up of any plausibly chopped-down IR would be the FAA IR takeup in Europe - at a guess, looking at IFR tourer sales, ~ 100 per year. The UK-alone historical IMCR takeup is 3x that!! The FAA IR takeup is of the order of 10x of the JAA IR takeup but that doesn't mean much because the JAA takeup is so close to zero (single digits/year in the UK, once you exclude the ATP pipeline crowd).
I don't know the answer. EASA does want to push an "IMC privilege" for PPLs and has done from day 1, more or less. If they didn't, you could forget it and an IR would be the only game in town.
It's all politics, so it's quite possible that the pressure to accept a low level IMC privilege (note: the name "IMC Rating" is a bit of a dirty word in Euro regulatory circles, alongside "FAA") may in fact ease in a substantially different IR.
Australia has an IMC privilege, done as modules. The 1st one gives you IMC enroute only (SRA is the only non-mayday IMC landing option). The next one gives you approaches, or something like that. Eventually you can reach an ICAO IR. This is a good way forward - so long as the VFR-only GA lobby don't screw it up again.
The future will be interesting.