I think it's because documentation (and design) requires different skills than writing code. A great programmer is not necessarily a good writer or designer. There are rare gems, people who have a balance of such skills, but most of us struggle to write useful documentation, even the bare minimum necessary for others to get started - or any at all. The code, or the lead dev's brain, is the documentation.
A perfect example of this is documentation generated from docblock comments. Some projects only have such docs, and expect users to go from there. It's as if programmers envision their audience as another machine to program.
I feel similarly about business/marketing aspects of software projects. Many programmers seem to assume, "If you write it (the program), they will come."
Successful software is so much more than just the code, it usually involves a communal effort of various skills, especially human communication, including writing good documentation.
A perfect example of this is documentation generated from docblock comments. Some projects only have such docs, and expect users to go from there. It's as if programmers envision their audience as another machine to program.
I feel similarly about business/marketing aspects of software projects. Many programmers seem to assume, "If you write it (the program), they will come."
Successful software is so much more than just the code, it usually involves a communal effort of various skills, especially human communication, including writing good documentation.