Yes, this is a bit of a micro version of the "should people developing software be allowed to call themselves engineers": some people want a formalised system which guarantees that people have passed certain tests and have a certain level of experience, other people observe that many of our heroes and CEOs are bright autodidacts. Is it a good idea to pull up the ladder? And besides, technology shifts and there are plenty of people working on technologies that weren't invented at the time they graduated. Bill Gates dropped out of Harvard, Andy Grove was a refugee who would have great difficulty getting into 21st century America, etc.

I agree that a lot of vital expertise comes from mistaken attempts and the need to change strategies.