The report is not unfortunately an endorsement of the IMCR ! It points out the relative similarity of accident rates in the US and UK. Whether that can be turned into an argument for an IMCR I doubt. It may be an argument for a more easily obtainable IR, but the report does not say so.
If you read the report fully, you will see that
it does indeed argue for a more easily obtainable IR, which is about all they can do, hamstrung as they are with airspace and rules which could not permit an IMC rating.
It also cites the British NPPL as a good thing (in the context of a sidestep from JAR-FCL) Given these points, and the fact that their fatal accident rate is twice as bad as ours, it is an endorsement (albeit tacit) of the IMC rating, and shows where we will be without it.
A few relevant parts loosely translated:
"JAR - FCL: A training system poorly suited to private pilots
The JAR-FCL training system is concieved as a professional qualification structure, because it aims to train pilots from ab-initio and bring them to a professional level, (CPL, or ATPL) whether by the integrated route or the modular route. In this second case, the training for a PPL constitutes the first step on the route to becoming a professional. The training programme is therefore conceived and implemented with this view, without being particularly adapted to pilots who consider the PPL as their goal...."
"Certain countries, such the United Kingdom, becoming aware of limits of JAR-FCL decided to impliment a National Private Pilot Licence, whose privileges, naturally, can be exercised only within UK airspace.
It is in this framework that we look towards private IFR flying: even though the JAR-FCL Instrument Rating concerns probably a very limited number of Private Pilots, due to the implicit requirements and costs (maintaining an appropriate level of currency requires regular practice on relatively complex aircraft), it doesn't make it less true that the qualification itself is percieved as very difficult to obtain. The major obstacle cited, with good cause, is the theoretical training, the requirements for which appear dis-roportionate to real need.
Henceforth, nothing should oppose the implementation of an Instrument Rating theory appropriate to the PPL"