Comment by adrianmsmith

> Quite frequently though its outsourced development agencies that refuse to write it

It's also completely against their interest to write docs as it makes their replacement easier.

That's why you need someone competent on the buying side to insist on the docs.

A lot of companies outsource because they don't have this competency themselves. So it's inevitable that this sort of thing happens and companies get locked in and can't replace their contractors, because they don't have any docs.