Generally speaking, when you go to confirm a prejudice, you get it confirmed. Everyone walks away happy. Yet the continuous pressure from the market plants another seed of doubt that drives the attendee back to the next meeting, just in case. None of this is helped by some consultants too willing to help you get ISO certified. The barrier to entry is low, the requirements few, and the mystique so thick you can't cut it with a chainsaw.
Objective evidence is to the contrary.
No quality shortfalls. Weak areas get identified by audit and required fixes are put in place on a time schedule. No magic, just a company in alignment with its customers and a shared direction for improvement. Companies who have held on to their certificates for three years or more have enjoyed startling improvements. One improved their defect rate by an order of magnitude.