>>29084380They've let companies release 3DS games without any 3D for years now.
The reason they're doing it for SM is probably because people complained about the framerate in XY and ORAS enough and GF isn't competent enough / couldn't improve it with the ridiculous models they're forcing the 3DS to process.
Pic somewhat related. SSFVI3D normally runs at 30 fps even with the 3D slider all the way down unless you go into the in-game options and completely disable the 3D. Then it runs at 60 fps. I don't know why any other game didn't just offer this solution because it's obvious that just having the option to turn the 3D on and off on the fly takes up processing power even with the slider set to off.