Dick,
I am generally on your side but when you don't respond to civilized discussion in a constructive way you make it hard to support you....
Compared to the likes of Charlotte, Boston and Houston (Class B) the likes of Fayettville, Lexington and Huntsville are pretty minor(class C). Your hypothetical IFR in the USA without ADS-B is fairly limited in where they can go.
You Said "An IFR pilot will be able to operate to hundreds of class D and E airports across the USA without the cost of ADSB. Even be able to operate a full IFR flying school from a class D tower airport complete with dual ILSs and then do multiple approaches and training to class E approach airports with no expensive ADSB fitment."
While this is true the FAA part 61.65 requires:
(ii) Instrument flight training on cross country flight procedures, including one cross country flight in an airplane with an authorized instructor, that is performed under instrument flight rules, when a flight plan has been filed with an air traffic control facility, and that involves--
(a) A flight of 250 nautical miles along airways or by directed routing from an air traffic control facility;
(b) An instrument approach at each airport; and
(c) Three different kinds of approaches with the use of navigation systems.
While what you say is possible in practice it would be a very limiting thing to be operating at a a Class D airport without going into a class c zone.
Do you advocate ADS-B for VFR flights in the same way that the USA will require after 2020?