Super Mario Maker producer Takashi Tezuka stated during E3 that they decided to add Super because the current game is (obviously) has more feature than the E3 2014 demo so people will know how different it is. However, the biggest reason is if they just call it Mario Maker, people will think they could create any Mario game level, like Mario Kart etc. So they add Super to explain the game is only about Super Mario level.

Full story http://www.technobuffalo.com/2015/06/29/nintendo-explains-why-they-added-super-to-the-mario-maker-name/

Sorry if this thread has been made before. 

PS: Actually the information is coming from GameInformer, however the link didn't work so I use this instead.

You know, there is Super Mario Kart.

Technically, the game is not the "main" Super Mario series.

I never thought of that but okay, there might some who would get confused.

I thought it was for continuity reasons. I mean, the levels you can make are based on Super Mario Bros,Super Mario Bros 3, Super Mario Word and New Super Mario Bros. See a pattern there maybe?

Super Mario is Mario after getting the mushroom power-up. Mario games that have this mechanic are called like this, but there are intruders from spinoffs and 3D titles.

Makes sense actually

Wait.. You can't make Mario kart levels?

They should add Ruy skin into the game. And market it as Ultra Super Mario Maker.

yes. it make sense. It is Super Mario games!!!