It seems to me that at this point people are being lured away from the fighting game genre to the MOBA and RTS games. Simply because these games have great support from the developers/publishers right from the gate, and are specifically made for a tournament environment along with great sponsors, and an instant audience due to the fact that most of those games are free to play from the get go.
I feel fighting game company's should start promoting tournaments as a marketing campaign to not only sell their games, but to also create awareness of the tournament scene. I personally did not know there was a FGC until Mortal Kombat 9 came out, and I have been playing fighters since sf2. I think that as soon as you pop open your game case there should be a sheet announcing tournaments for the year, or at the very least a message of the day in-game listing upcoming events, to really motivate people to come out and meet new people, compete, and just have a great time.
Until then though, I feel things are gonna drop a bit unless there is some sort of big draw toward the fighting game genre in my opinion.