Many reasons. Primarily because of security and control of my information. Secondly because services like these tend to be short-lived and unreliable, if i host it myself i can trust it's there when i need it. And i hadn't considered the uploading time issue mentioned in a previous comment, but that is actually a very good point that self-hosting would solve as well.
I also just want to see the code because i think it's cool
I also just want to see the code because i think it's cool