A degree certifies that you've read and to some degree understood, the book.
Which could possibly be a very old book that has nothing to do with the things of today.
The books chosen in college courses are typically not of the "Learn Visual Basic in 21 Days" variety. They cover algorithms, data structures, hardware architecture, OS design, database design, etc. These are general topics whose basic theories haven't changed in some cases for over 50 years. These are topics you use over an entire career, not just until the latest technology fad gets stale like VB, Pascal, Cobol, etc. They are meant to give you the theoretical underpinning so that you understand why any computing technology operates the way it does.
What I've noticed is that the developers who dismiss college and those "very old books" is that they have a superficial knowledge on maybe a few pieces of technology. They don't really understand how everything fits together and works. Although, they may be decent code monkeys. However, if they run into any truly difficult issue that isn't covered in their "Learn Visual Basic in 21 Days" book, then they're SOL due to their lack of understanding in the fundamentals. You have to truly understand a difficult problem before you can fix it.
Further, as soon as the technology they know gets replaced, they are the first out a job because they don't have that deep understanding to enable them to transition to new ways of developing. Their future is the same as the Cobol programmers of today. The best they can do is pick up a different "Learn the Latest Fad in 21 Days" book and start over as a junior programmer in a different programming job.
"Marriage is low down, but you spend the rest of your life paying for it." -- Baskins