Not strictly true DFC. You may recall that there was Type A and B special rules airspace. Certain Special Rules Airspace was OK for IMC ratings, many were not, as you say.
I understand Englishal's point, having discussed it at length a month or so back. I am less convinced that having the theoretical ability to fly IFR outside controlled airspace has any practical meaning in countries outside the UK. Most places don't segregate IFR flights from VFR using controlled airspace in the way that we do, and insist on an IR for all IFR flights irrespective of the prevailing weather conditions.
Its an interesting debate, but perhaps an academic one only.
2D