Hello Lutz and Brian,
Yes Lutz you are correct in that ISO 9001:2000 dose not specify levels of product quality to be achieved, but one of the important differences between the current 9001:2000 and earlier versions is the required element of Continual Improvement (CI)
Whilst CI does not directly force the improvement of a product, it does by way of its ethos challenge organisations to look at all aspects of its operations to see how it can make its self better, and it has to prove that it is applying CI.
It would be foolish if an accredited organisation did not look at its product quality issues, as it would steadily become less competitive. Equally the failure of a organisation to recognise a significant product failure from customer complaints and to do something about it would almost certainly be reflected in some other aspects of its management processes that would be picked up during accreditation surveillance visits.
One of the difficulties with ISO9001, is that it means very little to the retail customer so organisations that operate close to or with the end user see little benefit in applying for it. - which is a shame because virtually all the companies that I have dealt with have found that the long term benefits of applying 9001 can be substantial.