A surprising amount of our everyday writing is comprised of these shared, canonical facts. Walt Disney's birthday will never change, and neither will Apple's market cap for November, 2018. When we write about those facts, we can rely on our own copy of correct, canonical data -- not a link to anything. An ideal research and writing program, as we aim Mimix to be, would also be able to alert you when and if your canonical information changes. In that case, you'll be able to retain and reference both versions in your writing. Most importantly, your future readers will, using the Mimix software, also be able to see where you got your facts. These capabilities simply don't exist in any of today's software.
I'd more suggest something like pijul, since it soon will implement something transclusion-like natively:
Has the author ever read an old encyclopedia or textbook? Most supposedly canonical information gets revised.
At best we can have a immutable version of a file (such as when using git), but you hardly ever want a hard link to a particular version. Dependencies inevitably change and need to be updated.