I'm kind of surprised this (doesn't seem to be) for the 3DS as well. I hope they at least make a companion app of sorts for it that can let you play levels people made, but not be able to make your own.
But the 3DS is totally capable of this so if they did come out with a companion app people would just complain that it isn't the full version. It's funny though since WarioWare D.I.Y. was on DS and all the Wii got was a companion app. If they do come out with a 3DS companion app it would be like the complete opposite of what they did with D.I.Y.
But yeah, I kinda wish the 3DS got something like this too. D.I.Y. was much deeper than this and the DS still got it.