The reason for Neo Geo being more popular than SNES in competitions is probably that the Neo Geo catalog was almost all competitive simultaneous 2-player games (as they doubled as arcade games), while in the SNES most iconic games are single-player. For SNES games with the simultaneous multiplayer mode (e.g. Super Mario Kart) championships are also healthy.
In my opinion SNES and Neo Geo were, each in its style, the best consoles of all time, and in general they have aged really well, as can also be seen by the persisting popularity of their games in 2017. I think this is probably because they were the pinnacle of 2D gaming. Of course 3D bought amazing possibilities to gaming, but for example the precious artfulness and attention to detail in Last Blade II (IMO a much better game than the overrated KoFs, by the way) is something I am still yet to see in a modern fighting game. On the other hand, when I play an early 3D game like many PSX releases, I just see things that can be done much better now, which makes the game look more dated.
The Neo-Geo is truly a way to bring games you would find in an arcade home while the SNES has long single player games which don't work in an arcade setting. So it's not that surprising the Neo-Geo games are more suitable for competition than most SNES games.
In my opinion SNES and Neo Geo were, each in its style, the best consoles of all time, and in general they have aged really well, as can also be seen by the persisting popularity of their games in 2017. I think this is probably because they were the pinnacle of 2D gaming. Of course 3D bought amazing possibilities to gaming, but for example the precious artfulness and attention to detail in Last Blade II (IMO a much better game than the overrated KoFs, by the way) is something I am still yet to see in a modern fighting game. On the other hand, when I play an early 3D game like many PSX releases, I just see things that can be done much better now, which makes the game look more dated.