[iamNumber4]

Documentation is a catch 22. We love having it, but it is a beast of burden create. We also feel the pressure from management or self imposed deadlines to get something done. So documentation is the first thing to slip.

You also can’t document everything. Well not at first. You always have gaps and most times they are filled when some needs something and it is not there.

Which then highlights the biggest issue, you have to maintain it. So since there is that constraint and burden, the sentiment is why have it. The source code should be self documenting. Yadda yadda

[ThJ]

Right, but that's the output end of it. What about the input end? Developers are also users of libraries and frameworks. My question is perhaps more about why poorly documented frameworks end up in production systems than why people don't write documentation (we mostly know the answer to this already).