Inadequate manuals aren't just caused by Microsoft. They are everywhere.

In 1980 I took a course in computer programming at a community college. It was taught by the head of the department, one of the pioneers of computer use.

He told us that when a company develops a new product, it almost always goes over budget. The writing of manuals comes at the end of the process, by which time the project is in the red, and management is jumping at every small, sharp noise. Naturally the least amount of time and money possible goes into the manuals. And it shows.