Thomas Coupling:
I don't want to go over this in nauseating detail again, but let's put in the bare bones. The NTSB report is not new, and pertains to a time before changes in procedures, mostly driven by Frank Robinson himself with his safety courses, his insurance arrangements, his demands of the FAA and his requirements of pilots.
Back then, the Robinson massively increased the number of civilian helicopter pilots and the number of low-time pilots. As a result, quality of piloting was poor, and the accident rate in the US was high. The situation was exacerbated by the 50-hour rule, which held that any fixed-wing instructor who had 50 hours rotary time could open up the boot of his car and set up shop as a helicopter instructor. Frank Robinson petitioned the FAA time and time again to have that rule rescinded, to ensure that only qualified helicopter instructors could instruct on helicopters. Sounds logical, doesn't it.
Any two-bladed rotor is unforgiving of low-G. The Army taught Vietnam-era pilots how to avoid getting into low-G problems in the UH-1 and others. Robinson didn't invent the two-bladed rotor, and he didn't invent low-G. Knowledge of how to recognise the problem and avoid turning it into an accident is fundamental to good instruction - unless, of course, you're a fixed-wing instructor who just happens to have 50 hours rotary time.
The R22, and later the R44 - which despite your post displays far worse low-G characteristics than the R22 - has always suffered from the attempts of other manufacturers to do it down. I attended the Paris air show some years ago with representatives of a major US helicopter manufacturer who made no bones about the fact that, especially since Robinson was producing the R44 "which aims to eat our lunch" he was a target. In the main they have made a good job of spreading fear and uncertainty about the R22, which by its performance, its reliability and its excellent safety record has nonetheless answered all critics.
As to your assertion that cost is the only reason why the R22 now outnumbers all other singles put together - don't be so bloody stupid. The R22 is bought by pilots who don't give a damn about costs, where their safety is concerned. If your claim were true, the sky would be black with RotorWays. Many cheaper helicopters have come and gone, so don't talk drivel.
Lu Zuckerman's got stuck in a groove that he can't get out of, despite his arguments having been comprehensively destroyed time and time again in this forum by authorities on rotor design and high-time pilots. He has long since blown his credibility on the Robinson, and anything he says about Robinson can safely be disregarded. Look at the facts, and don't just recycle the taproom prattle.