You are comparing public with private. The garage would go out of business if its service was poor, whereas the NHS is a communist monolith, and therefore poor performance and labyrinthine complexity is to be expected. Think of all those non-jobs that have to be paid for.
My underlying point was more to do with highlighting the lack of robust planning in some areas, thus leading to issues like increasing waiting lists and so on. I don't doubt there are some NHS roles that need not exist, i.e. the service would continue to function perfectly well if those roles weren't devised, however the same can most likely be said of many large organisations, public or private. And I suspect if the 'non-roles' were removed tomorrow, the positive impact on service delivery and more £££ in the coffers would be minimal. The issues go much deeper than that.