I don't believe most of the fanbase for Smash bros even thinks of it as a "fighting game" in the sense of comparisons to Tekken, Virtua Fighter, Street Fighter, King of Fighters or Guilty Gear, so I don't think it's gonna become a barometer for how much content needs to be in any of those series or others similar to them.
As someone who keeps up on gaming news, plays most of the big games and is pretty knowledgeable about what games are out there, I don't have VF5 or Street Fighter comparisons running through my head when I'm using Donkey Kong to kick the crap out of Pokemon characters. And for those who don't follow gaming as much as someone like me, I hardly think they;re saying to themselves "Well, the next tekken needs to have more game modes now that I've played this"