When Super Mario Maker released on the Wii U in 2015, many fans joked that Nintendo never needed to make another 2D Mario again – that the fans would ecstatically make the next generation of 2D Mario for them.
While it is interesting to imagine a large developer letting its community take the reins on a major franchise, in Mario Maker that wasn’t necessarily the case. With the blocks finally in their own hands, Mario fans didn’t want to create traditional levels, and instead proceeded to create eclectic and amazing new challenges that Nintendo never envisioned (or did, and deemed too frightening for the average player.)
Source: IGN.com The Insider's Guide to Mario Maker's Secret Language