I dealt with trainees who have achieved very little at school. NVQs offer the opportunity to receive training and recognition in many skills at many levels. The villain of this woeful tale is the policy of payment by results. Training providers receive a generous sum for each trainee that achieves any level. It so happens that level one receives the most generous bonus for the provider and a comparatively small financial reward for the trainee. It does not take a successful outcome in business administration to work out where it is most profitable to direct students. The more able are more likely to achieve the desired result in the shortest time, especially at level one.
As for the certificate not being worth the paper it is printed on, for students who have never had a piece of people of any sort, it is very valuable.