First of all, Gateway is a CFW. Your sentences make it seem like you don't know that so I just add the precision.
Then, there are several kind of people.
Then, there are several kind of people.
- Those who never had a Gateway. These ones don't move from Gateway to free CFWs, they just start hacking with a free CFW (since well, it's free you know). Obviously they couldn't do it when Gateway was the only viable solution.
- Those who don't use cheats. These ones could keep using their Gateway... but just like you're wondering "why switch?", actually, why keep a Gateway? It's just annoying to have to boot the 3DS with the red cart in. And Luma has some nice functions too, like custom splash screens (not the best feature I could think of but whatever )
- Those who use cheats. These ones are basically the only ones who have an actual reason to keep using a Gateway. Because yeah, NTR exists. But it's just like people who say there is Wine on Linux to play games. Either they never tried Wine or they never tried Windows, but you can't say it's a good alternative to Windows if you tried both. Same here, NTR is an alternative to Gateway cheats, but not a good one.