I am an advocate of developer documentation. I understand why smaller, less mature ISVs and IT shops would take the quick and dirty shortcut of forgoing developer documentation. No one wants to do it. It costs money keeping that documentation up to date. Programmers should get paid to write code. Blah, blah, blah.
Larger, more mature, shops should know better. They should realize that the total cost of maintaining large systems, over time, is much less when new developers can accelerate their time to productivity by reading some well written, accurate developer documentation. Also, it's nice to throw the developer documentation at the powers that be (i.e. government, acquiring company, BOD) when they want to know what's really going on. I'll bet that Microsoft wished that they had spent some more resources on writing good developer documentation.
You don't like to do it. I don't like to do it. Nobody likes to do it. But writing quality developer documentation is like filing your taxes. Doing it is better than suffering the long term consequences of not doing it.