Mario Maker was originally developed as a course-making tool for Nintendo's internal development teams, according to Nintendo's executive officer of its Entertainment Analysis and Development Division, Takashi Tezuka.
Tezuka told Polygon the people on the tools team typically don't design video game courses — they only build the tools for Nintendo's game designers to use. In this particular instance, the tools team was working on a Mario course editing tool when they decided to pitch it to Tezuka as a standalone game.
"They brought the idea to me thinking it would be a great game idea because they had so much fun with [it]," Tezuka said.
Tezuka also told Polygon he'd been meaning to make a new Mario Paint game that uses the Wii U's GamePad, and he saw an opportunity in Mario Maker to make a game that encourages players creativity in a similar way to Mario Paint.
"There are lots of drawing utilities in the world, but does everybody like drawing? Not necessarily," he said. "In order to make a [Mario] course, all you have to do is put different parts together. It's not as difficult or out of reach as drawing is. Instead of creating another Mario Paint, when I saw this course editor, I was inspired to bring the fun of Mario Paint into this course editor to make something fun and creative for people to enjoy."
Tezuka said he completely expects people to be silly in their course designs and to create levels that are impossible to complete, and that's the point: Mario Maker isn't just about finishing courses, it's about enjoying the process of creating a course, no matter how silly or impractical it may be. He gave an example of a team of Nintendo employees who created a course that required Mario to run to the end of the course, then run back to the beginning, then run back to the end in order to complete it.
"We think this is a game that will showcase people's sense of imagination," he said. "Seeing the courses made by [those folks] made us realize it had much more potential than even we imagined."