[pydry]

You're right - I think a lot of people don't care.

However even if you take out the replaceability I still think that there's a relatively limited upside.

Thus you're left with conscience or a sense of professional pride as motivators to write docs.

[aflag]

Yeah, there are no incentives. No one will praise you for writing them, they will probably not be well maintained and other people will make changes and not update them. People will still ask you privately instead of reading the docs and will get annoyed if you tell them to read the docs. You yourself will likely not really refer to them anyway, as you probably already have them memorized for the 3 year period when they are relevant to you.