I think once again we are misinterpreting what he is saying. Which is understandable, because first his words are recorded in text and then translated, and then finally we have to read it ourselves.
He seems to be saying that Smash isn't a very good competitive game because, for example, it doesn't have as many inputs or as high of a technical skill curve than other games... but wait, no he isn't saying that. First of all that makes no sense. We all know Smash Bros is a genius franchise that has so much depth and complexity but with much simpler and more intuitive inputs than traditional fighting games. So what is he saying?
When he's talking about serious gamers, hardcore games, and competitive fighting games, he's specifically referring to games that have a high technical requirement. When he's saying that you need skill, he's talking about technical skill. That's why when he talks about the kind of "competitive game" he does not want, he compares it to a sport, because they are hard to play physically. Not because he thinks depth and complexity (strategy, mindgames, etc.) are bad. If he did, he wouldn't compare it to sports but to chess or starcraft or something.
This isn't the first time he referred to technically challenging games as "competitive" games. In the past he's described such games as "maniac" and "hardcore" (the latter of which he uses here). When he says he can make a more hardcore game, and that he can make it fast and increase the inputs, he is alluding to Melee (intentionally or unintentionally). Therefore, he is NOT saying that Melee is a better competitive game, but rather the only conclusion you can make from what he's said is that Melee simply is more technically challenging.
I think when you look at it in this perspective, this initially confusing statement makes much more sense
Actually there are possible 2 interpretations of this (does anyone know what the japanese really means?), but they both support my interpretation.
1) How do you make something entertaining to spectators? Have the players do crazy techs, which would "downgrade" the game because he doesn't want it to be technically and physically demanding. He wants it to be easy to learn, impossible to master, but without a high technical skill floor too.
2) How do you make something more spectator friendly? You make things easier to see and understand, and that means removing advanced techniques, depth, and complexity. Surely removing those things would make a worse [competitive] game, and indeed he agrees that it would be a bad thing.
His next few words confirm that he's referring specifically to the unwanted physical aspect of the more technically challenging games.
I'm sure we can all agree on that. Easy to learn, impossible to master.
So no, he isn't saying Melee is a better competitive game than Smash 4, and he isn't saying that Smash 4 has no future as a competitive game. Replace his use of the word "competitive" (remember translating will lose connotations and twist meanings) with "technically difficult", and reread his words:
Smash 4 as a technically difficult game has no future if you are expecting it to be like those "hardcore" games that have really high technical skill requirements. He isn't saying anything against Smash 4's design and he isn't saying that Smash 4 was not made to be a good competitive game. He's talking specifically of the act of Smash 4 being played by people who desire a very technically demanding game, and that Smash 4 won't satisfy them. Hence, it has "no future" as a technically difficult game.
In the interview he says that he thinks it's good that Smash 4 can be played in so many different ways, which only supports that he is happy that people play Smash competitively. If you interpret his words so that he doesn't think Smash 4's competitive scene has a future, that interpretation would contradict this.
This is what I currently think, open to change.