[fjfaase]

Probably because they were autodidacts that got frustrated with following courses that were either not relative to what they already knew or far below the level they already had achieved.

When I went to study CS in 1981, I already had mastered Fortran and LISP. I did not learn anything new about programming languages until my second year in college. The new concepts were currying and lazy evaluation. I did learn a lot of other things thou. Primarily about mathematics: calculus, algebra, graph theory, combinatorics and statistics. Also some about electronics and digital circuit design.

But when I started working as a software developer, I also realized that much what I learned at the university was not relevant and that I could have done without much of what I learned there. I still happy about my time at the university.

A degree is more a proof of that you have the ability to master certain material than a proof you know what is being taught. I that view it is more of an entry exam for certain job positions, although for certain companies, especially in the US, that no longer seems to be the case. But that does not mean that people without a degree are not able to perform as well as does who do. This might not be true for all fields of study, such as law and medcine.