I'm 34 now. Started with fighting. Probably in 1987 with Mat Mania. Saw my sister's friend do a command move where he was in the ring and the opponent was outside he ran and fell on top of him. Simple to nowadays but I was hooked since.
SF II WW was where I saw real competition for the first time. 42 year olds playing the 10 year olds all trying to figure out this amazing game. Nowadays it seems everybody can do a qcf motion, but back then to see someone pull a fireball out was amazing.
I was very active in the local community for years. Supporting SNK, Capcom, and Namco mostly, but I did play other titles. It's aways been an uphill battle for fighters once you get into the mid 90's the wow factor wore off and you would constantly see people look for the next game to shock them. Whether it be Tekken 3 and above, Soul Calibur 2 with the console exclusive characters like Link, and Heihachi (nobody I knew really cared about Spawn), or more realistic fighters like Bushido Blade, the crowds constantly moves towards something else that could amaze them. The hardcore group could be found, but as we all know WE don't have the final say.
Nowadays this new generation IMO gravitates either toward the easier to get into fighters like Smash Bros. , or recognizable games like Naruto, Dragon Ball, etc. Street Fighter IV was kinda a fluke cause of people knowing all those animes saying "Hey I know Ryu!". Copuled with 3d graphics that the new generation wants to see. Similar. IMO is Mortal Kombat with all the media surrounding it The new generation can identify a bit to the story from the movies and tv shows. KOF just didn't have much susccess in the media market except for Fatal Fury which IMO is why Terry Bogard is so popular.
I have brought a system or 2 to an anime convention. It seems most would either want to play Smash Bros or Marvel vs Capcom. It's kinda sad but if the kids don't already know your product, then there is a hesistancy to pick something new up.