ELI9: why is John Carmack being accused of copying code while he was one of the most important programmers to have contributed to First-Person gaming and real-time 3D visualization on the PC platform?<p>Why should he, among all programmers, be considered guilty of copying other people's code, when he was the first one to make several 3D engines open-source and 3D real-time visualization software is most likely to be derived from his work and algorithms?