First of all management systems and ISO is a way of working, a method or a framework. Just like scrum and agile are methods for project management within a team, management systems within the context of ISO is a method or framework set up by the management to lead the company. If you don't believe in ISO as a method, then you should not do it. Simple as that.
Personally however I think that ISO and management systems solves a lot of the problems that most companies deals with, and it gives a structured way of setting goals and reaching them.
Secondly the certification is not the most important part. The certification proves that your management system works and that you are reaching your goals, but if your goals are shit then the certification rather proves that you are a shity company. In other words the certification in itself is not a quality badge.
Personally however I think that ISO and management systems solves a lot of the problems that most companies deals with, and it gives a structured way of setting goals and reaching them.
Secondly the certification is not the most important part. The certification proves that your management system works and that you are reaching your goals, but if your goals are shit then the certification rather proves that you are a shity company. In other words the certification in itself is not a quality badge.