The only thing that I can say AL, is that yes you are right! There are water conditions where, no matter what you do it is very difficult - almost impossible to right any cat (and/or dingy) but those are exceptional conditions where the actual water conditions are the problem, not the righting technique.
In winds up to 18 knots odd (true wind speed) I have personally righted a Tornadoe on several different occasions, and on others I have been unable to right a 14' cat, no matter what I did in winds that came up to over 30 knots with very (very) steep breaking head waves very close together. Every time I looked like getting some where a wave would break and sweep the cat around and slam me down and I had to start again. I don't say that any method is fool froof, but there are methods better than others and if people are going to sail then they should at least "have a fighting chance" of survival.