One of the problems is that SRATCOH is/was a very large sledgehammer to crack a very small nut. When the committee reported, they found ,overall, very little evidence of fatigue being a cause of incidents. But, having measures in place to prevent the possibility seemed sensible. Hence, we got SRATCOH. In the regulatory environment at the time, it was probably the best that they could do.
It is proof positive that one size can't fit all. As Keith rightly said, his unit worked harder (hmm) and longer under under the rules. Could quote several other units that suffered too. Wish I could list all the names I was called at the time for being the poor sod trying to implement it!
Theoretically, a good SMS system should allow units to tailor the requirements to better suit their operations. Interesting to see how that works.
Last thought; the regulatory regime these days is based on "hands off regulation", i.e the companies know their business better than the regulator and should be trusted to apply their SMS correctly and safely. Worked well at Boeing!