[dspillett]

A couple of immediate thoughts:

1. In many cases the books were published by Microsoft Press, so the company benefitted financially as well.

2. The engineers may have a defences in not being given time to document better initially due to project deadlines beyond their control, and in the work being signed-off at the time.

3. Some of both the above mixed with other reasons.

[rob74]

4. they probably also didn't have the time for better API design, or the API design was done "by committee", and if you add to that the holy cow of "backwards compatibility", it's easy to see how an API might end up overcomplicated...

5. maybe M$ even encouraged these practices because of the perceived advantage for in-house applications vs. third party ones?