Those people may be few and far between on SmashBoards, but the competitive community is a very tiny percentage of the individuals who bought/will buy this game. .
I hear this a lot, but this has totally changed. Not really just for Smash, but for videogames in general.
Just because the tournament-attending population is low
no longer necessarily means that barely anyone who gets the game is aware of the competitive side of things. In this modern age, if a game does not have a large population of competitive tournament players, that does
not mean that many players do not enjoy playing in a similar competitive fashion for fun on their own.
E-sports and tournaments is only a part of the picture - internet spectating is huge now. People love watching people play at high levels now, and they appreciate it in almost any kind of game. The barrier of "Oh, Smash is a casual game" isn't a negative anymore, even moreso because Smash 4 has a heavy built-in competitive aspect.
The demographic of 'casual competitives' is enormously high now. They are the thousands of people who watch competitive Twitch streams and youtube videos - yes, even Smash. The 175,000 people who watch each of Husky's Starcraft2 videos are not all tournament competitors - they are mostly spectators and low-level Starcraft 2 players who enjoy competitive play, and many of them play the game that way themselves. Twitch, LoL, DOTA, Starcraft, and competitive FPSs are very popular now and in the collective consciousness of many gamers now, even if they aren't part of the small % who actually compete at tournaments.
Not every player who plays LoL is a competitive player, but they're all aware of the competitive side of the game and the fact that players go to tournaments. And that's the accessible MOBA - the one that non-hardcore gamers feel invited to pick up.
Yeah, Smash 4 isn't in the same "obviously-attracts-the-competitive-demographic" league as LoL and Starcraft 2, but all that means is lower population in general. Smash 4 is still a new and exciting fighting game, and a large spectator demographic is certainly growing in line with other games.
Smash 4, due to changes from other Smash titles (especially with For Glory mode introducing everyone to competitive play) is very much in a similar "accessible competitive play" boat in the fighting game market as LoL/SMITE is in the MOBA market. Many players are interested in competitive play, even if they don't compete themselves.
A clearer way to see this is Project M - it is something many people know about and play, yet not everyone is a competitor at tournaments. This is because the population of 'casual competitives' is much higher than any of us really appreciate. Many people know that Smash is played competitively now and are interested in playing more in-line with how the game is played at tournaments, even if the competitive playerbase itself is very low.
Of course, this was NOT the case a year or two ago, but Smash 4 hype - along with the growth of Twitch/Project:M/Melee/Pro-Gaming in the past couple of years - has changed things immensely in the video game industry.
TL:DR
Competitive play is no longer a tiny % of the way people enjoy playing (and especially watching) Smash any more.