I feel like there's a place for Sky3DS, Gateway, and every other CFW.
Sky3DS is nice for those on non exploitable firmwares, and for those who aren't tech savvy enough to go through setup and just want something simple and works.
Gateway is nice in the fact that you can use the cartrage as a way of playing game. Kinda a mix of a Sky3DS and a CFW, but with the added bonus of having a easy way of swapping games then on Sky3DS.
Then there's CFW, for those who don't have money or don't feel the need or want to use a Gateway.