I know that is a nice cliché that people like to toss around, but I don't think there is a whole lot of truth in it.You were not raised in the environment where everyone gets a trophy for everything they do. You just have to understand that, for some people the card is more important than the skill.
I just measured my stack of certification cards, and it is just about 2 inches high. I only need a small percentage of them, like the Overhead DPV card I have to show to run a scooter at Ginnie Springs. The rest were just something that came with the training I got. I took a class and paid for it because I wanted the training, and I got a card when I did it, whether I wanted it or not.
As Ii said above and people don't want to recognize it, there is a legitimate reason for it. The card signifies that it was an approved course with an approved and predictable curriculum and not just something somebody made up. The primary benefit is not to the student but to the instructor who can defend those procedures in case of an accident by saying that he or she was just following the standards approved by a recognized agency.
There seems to be an underlying thinking in this thread that professional instructors should not be paid for what they do. They should volunteer their services so that all students can learn whatever they want without having to pay for it. Why should that be different from the rest of the world of instruction? When I was in Boy Scouts and learned something, I got a merit badge. When I graduated from high school, I got a diploma. I have taken an enormous number of courses of many kinds in many places. I am having a hard time thinking of any that did not provide some sort of certificate when I was done. Why should scuba be different?