The RepRap project and the derived printers tend to share the opposite philosophy - the original idea was to print parts for more printers, so naturally parts w

The RepRap project and the derived printers tend to share the opposite philosophy - the original idea was to print parts for more printers, so naturally parts were designed to be 3D printed. The RepRap logo is a compromise design for part holes without support (no longer necessary, though). Most RepRap owners ('hobbyists') are using the 3D printer as the end manufacturing method, not just for prototypes, so this is a pretty reasonable tradeoff. Note that the original article fell into this category - the 3D printed part was not a prototype, but a jig used in production. (looking at that part, it could have been designed to not require any support material at all)