They don't write all the code from scratch. A good bit of the backend stuff is done by the Ubuntu and Debian developers. They do amazing stuff though. It's no coincidence that Mint is my only OS on this computer.
*Also rant/offtopic* what is up with everyone posting irrelevant pictures? Is this site being confused for 4chan now?
EDIT: Gotta love censoring. Whiskey Tango Foxtrot to "confused". That one actually made me laugh.