It is made so that it is later possible to understand who sent what, when and why.
I think that's a good problem to solve. Just a few minutes ago one of my coworkers walked over to another coworker's desk to explain a file they just uploaded to Dropbox.
It really is. File-sharing nowadays is half way done. It works good to share files across devices, but it lacks context in case of person to person sharing. Now we just need to understand how to present our solution, and you just helped us a bit, thank you one more time.