Windows is actually much closer to this limited, meaningless, form of the "everything is a file" meme. In Windows literally every kernel object is a Handle. A file, a thread, a mutex, a socket - all Handles. In Linux, some of these are file descriptors, some are completely different things.
Of course, this is meaningless, as you can't actually do any common operation, except maybe Close*, on all of them. So them being the same type is actually a hindrance, not a help - it makes it easier to accidentally pass a socket to a function that expects a file, and will fail badly when trying to, for example, seek() in it.
* to be fair, Windows actually has WaitForSingleObject / WaitForMultipleObjects as well, which I think does do something meaningful for any Handle. I don't think Linux has anything similar.
