Dick,
You are now becoming irrational. For MY part, I never supported E airspace, especially non-radar E, and you know it. The only reason that AIRLINE PILOTS "no longer supported" E airspace is because, even with transponders, it tried to kill a few of them (and hundreds of pax). Or does your memory fail to remember 2004? E airspace is a furphy Yankism. You just cannot have two separate airspace systems mixing it without some sort of coordination.
Anyway, back to your tit-for-tat cost to GA. I'll add to the list above that another reason GA has declined is that because you have changed every rule 10 times in the last 15 years that many have just lost interest. if you can afford to buy a $100k+aeroplane, a $1000 transponder is a detail!
SCE to AUX,
With Class G airspace (and the Class F that you have in Australia), pilots must do their own separation, usually to no real standard and at best to a variable standard. As you correctly point out pilots need extensive training, and authorities around the world won't be letting airlines do that any time soon.
Provision of Traffic Information is an ICAO-approved IFR service aka Class F. In 30 years of flying in Class F (call it what you like Dick) I have never been scared when I have known about other IFR traffic and self-separated from them after having been trained in the technique by my instructors. All I'm saying is that there are tricks to self-separation with ADS-B that we will have to be trained in. Your average Joe Blow with have the TCAS bleating if they say "oh there he is we'll just turn this way a bit and miss him".
It all boils down to what the biggest threat is. IMO, it's VFR in the terminal area, hence the need to have transponders on them.
[B]Gaunty[B],
ADS-B is fantastic, I agree. you just have to listen to the shamozzle over the Pilbara every day. But are we gunna pay for it voluntarily? Nuh! I was just pointing out that in the late nineties it was touted as the panacea of self-separation but when UPS tried it, they got themselves into trouble on quite few occasions (as crew, now instant fighter pilots, tried dodging each other) and if my memory serves me correctly, the trial was stopped on safety grounds. With the benefit of hindsight (and specific training) it is now being trialled for self-separation but we are miles way from "point where you like and play dodgem cars to get there". ICAO are only just now talking about using ADS-B and TCAS for oceanic in-trail climbs!