Alex Heney Kev is not saying that the legally enforced speed limit *is* the safe speed. Yes he is. He certainly is not doing so in anything he has ever written.
Apart from what he wrote earlier that is. Here, I've brought it down for you:
Exactly right - but the problem is that many drivers require a legally enforced speed limit to ensure that they do so. (in response to the suggestion that one should drive at a safe speed).
In the above he said that if you comply with the legal limit, then it is *more likely* that you will be driving at a safe speed.
He said that later.
That does not say you cannot be driving at a safe speed without complying, just that it is less likely. He is saying, quite correctly IMO, that if there *is* a legally enforced limit, then more people will drive at a safe speed (not necessarily at the limit). That's probably what he meant. It is what he said.
Maybe you should read it again, and also try to remember that nit-picking pedantry is not something to which you have exclusive rights.
-- Rob