I certainly was not trying to suggest that flight crews work harder than anyone else, nor indeed that other people do not work long and hard hours. What I was saying was that just because people in other jobs work long hours without a break does not make it sensible or safe. The rest mandated by CAP 371 is based in much scientific research, some bloke you know that does 18hour days is hardly scientific. Besides as was mentioned, flying (amongst some other industries) is safety critical. Doubtless those safety critical industries also have regulations to ensure safety. Even the UK medical profession is being kicked screaming and kicking into the 20th century - much to the annoyance of senior doctors. They are looking hard at aviation to avoid some of the errors that being human causes. "Is the right leg the right one? No, the left leg is the right one" - which is why we number engines to avoid confusion.
Rather than question why crew get provided with adequate rest facilities, perhaps the question ought to be why many industries do not provide such facilities. The flat beds in J and W are part of those rest facilities that companies provide (through the ticket price) to allow people to go to work straight off the plane.