Anyone who grew up playing Sonic games in the 1990s knew that the lead villain was called Dr. Robotnik. He had henchmen and other subservient robots under his command, and it only made sense given his name was Robotnik... right? Wrong. Robotnik was never supposed to be his name.
GameZone singled out a quote from an interview that Game Informer conducted with Sonic Team's director Takashi Iizuka. They're currently working on a brand new Sonic game that will be unveiled this year, a new generation of Sonic. Iizuka explained to Game Informer that Robotnik was a name that Western localizers came up with but they never consulted with the design team before making that change...
It wasn't just popular, it was iconic.
Everyone identified Sonic's main villain as an evil genius doctor... a doctor of robotics. The moniker Dr. Robotnik fit like a glove because it not only quickly identified him as someone who relied on mechanical underlings to do his dirty work, it also easily established him as a maniacal genius; a bright mind gone mad.
The name stayed within the Sonic games all the way through the 1990s, and was even the name used in the various cartoon iterations that came out during that time as well. Sonic and Dr. Robotnik were a pop-culture phenomenon, similar to Mario and King Koopa (the latter of which would simply become known as Bowser by the time the N64 came around).
Iizuka and the rest of the developers were not pleased with the change in name. They had made the oval-shaped villain Eggman and they were going to stick to it. Iizuka further explained...
It's unfortunate because Dr. Robotnik was such a unique and fitting name for the character. While th egg-shaped Eggman obviously plays on his conspicuous shape, it was the more subtle and nuanced Dr. Robotnik that won fans over.
To this very day most fans will agree that Dr. Robotnik just rolls off the tongue easier and seems both prestigious and fitting for Sonic's arch-villain.
It's also interesting because as Robotnik turned into Eggman, the games started to get worse. At this point most Sonic titles feel like parodies of the original, but Sega is promising to get things back on track with the new 3DS title Sonic Boom: Fire and Ice and the currently unannounced Sonic game due out for the new gen consoles. Sadly, if you were hoping Dr. Robotnik would be making a return, you're fresh out of luck... it's going to be Eggman forever.