It's particularly silly in the humanities. At one time, we expected professors of English and philosophy and so on to be _learned_, i.e. to actually know their subjects forwards and backwards.
At Oxford and Cambridge, English degrees were only introduced in the
1920s, and the requirements for a BA in English included being able to read and write the English of all periods, including Anglo-Saxon and Middle English. That went away in the 1960s, I think, along with a lot of other good stuff.Then the humanities got the 'originality' bug, which has been a huge disaster for learning in general--you don't get tenure for agreeing with your predecessor.
In engineering, the basic professional qualification is a bachelor's degree, whereas in science, it's a doctorate. The narrow specialization of Ph.D's in engineering is not typical of most scientific disciplines IME. The skills are just different. I was fortunate to have a brother who taught me how to solder at age 10, but then I went and did physics and astronomy and math and all that stuff--I've never taken a circuits course in my life, unless you count the jokey RLC-circuits-for-scientists class they made us take as sophomores. (I could have taught that course at the time.)
Spending 20 years at school won't make a fool into a wise man, but if you have a few brain cells to rub together to begin with, it isn't always wasted. ;)
Cheers
Phil Hobbs