I can imagine any number of situations where it might be wanted. Keep the file open in vim, changes are made from somewhere else, but you'd like to keep the original version, so you :w. It makes sense to me the :write actually writes regardless of context (assuming sufficient permissions) and with no hidden conditions like "something must have changed". That kind of thing leads to weird user behavior like editing whitespace just to be able to re-save a file.

Vim is from an era when software was written to do exactly what you commanded it, not what you intended. It was your responsibility as a user to learn how to turn your intentions into commands.

If you tell it to write, and it doesn't write, then it is no longer your tool, but rather someone else's tool that you happen to be using.

Why would you ask it to write if you don't want it to write?

Because you told it to write.

Its one of the things about exiting Vim. If you type :q, and there are unsaved changes it will prompt you to save it first and not let you quit.

So most people do :wq so that it saves and then quit or do :q! to quit without saving changes. Most people stop using :q.

Because it commands to “write”. Also related to 'autoread'.

There are strange cases which may make this a logical choice. Since vi doesn't traditionally lock the file it's editing, another process could change the file on-disk while you have it in the editing buffer. I think you'll get a message in these situations, because it's usually not what you want. Then you'd have the choice of writing out the buffer, whether it's changed or not, to restore the contents of the file from when you began your vi session.