Cool figures. Killer Instinct was big back then. I also remember Killer Instinct 2 being big in the arcades.
Nowadays it's not as popular but that's also because it's developed by an unknown studio (double helix) and is exclusive to an unpopular console. I'm not sure that's basis enough to say it can't compete in terms of quality per se, except for the developer part. However a developer can change over time, the franchise itself still holds a lot of potential.
Then again, you might be right that during this generation not much will be able to compete with SFV in terms of quality and popularity except Smash. But time will tell. V might just be another SFIII.
Just so you know Double Helix isn't developing the game anymore. Also we know the quality of KI, just look at metacritic or read peoples impressions. Now we have just to wait and see whether SV5 will be good.