I'm not sure I buy this argument. If you have one candidate who has seen all of this stuff before and can use it directly from memory, and another candidate who has been busy raising kids and has never seen this stuff before, who do you want to hire, all else being equal?
I could make an analogy to seeing a doctor. Say your kid is sick with a high fever. Do you want to see someone who did an EMT course at a local community college and hit the basic highlights of how to treat different symptoms, or do you want to see a doctor who had to take everything from organic chemistry to biology to anatomy to pharmacology courses? Sure the chance of any given piece of that training being relevant is small, but you want someone whose decisions are informed by a deep knowledge of the field.