For example, if you have a resource that's in development and there's no download file available yet but you wanted to add it as a resource so you could track updates it would make sense that once a file is available for download you could add it directly into that resource. As it stands right now you have to create a completely separate resource and loose previous updates and reviews to achieve this.
If this features is not added then the wording of the "Does not have a file" description should be changed. Right now it reads "There is no download available yet." The "yet" implies that there could be a download available in the future which will never be possible for that resource with the current setup and is misleading.