If you create something with Arduino and put it out into the world, there is no well-established link to the source. If you personally made the device, the source can get lost over time. If you didn’t create it, you could have a tough time tracking the source down. You have the physical device, why can’t it tell you where it’s code lives? I made a tool for Arduino called “Upload-And-Retrieve-Source” that for the most part solves this problem.