Pontius, the people you quote have the means to fund the infrastructure and except for the military, are commercial operations that recover the cost in their fare structure.
Ovation, whilst it appears those people have the means, we surely have to ask how they got them in the first place and how they should be spent. Obviously the military and Government organisations get them from the taxpayer and the airlines get them from their passengers. However, why should an ordinary taxpayer have their taxes, or an airline passenger have their ticket prices increased, to fund radar coverage all over because Dick Smith doesn't want to pay to get ADSB fitted to his aircraft but, instead, uses specious scud running crash examples to drum up support?
I agree that the chances of bashing into someone are incredibly small but that doesn't really help Joe the ATC who has to provide standards of separation in an ever reducing airspace (or more aircraft, however you wish to view it). The world is moving on and we cannot continually say that how we did it in XXXX worked okay. Procedural control is incredibly inefficient. It may have worked with the lower traffic numbers of yesteryear but it's binding the hands of ATC and has no future-proofing (sorry for the management babble). ADBS, along with RNAV etc not only make things easier and more efficient for ATC but save money with direct routings etc and has development potential, whereas scores of miles between procedurally controlled aircraft, following necessarily mandatory courses, does not.