Everyone who works commercially should write properly documented code.

All assumptions should be described.
Any requirements when setting up the project (which may possibly need to be redone if switching to a different tool)
Important reasons for design decisions.
How to test different functionality.
Any timing requirements.
...

For evaluation boards, the customer can be seen as a student buying an educational kit. So the teacher must be pedagogical.

But for normal projects, it must be assumed that someone else - possibly not well-versed on the specific hardware and/or compiler - may for some reason have to take over the project.

At that time, the compiler may no longer be possible to buy. Or maybe Microsoft have made it impossible to run the tools. Or the tools may have been so much upgraded that they can't process the old project files. Or the compiler may have been updated to a language standard that no longer uses specific compiler extensions.