"Mmm. Personally, I feel that if you want to play a fighting game seriously, there are other competitive fighting games that are more suited to that, and people like that could have fun playing those. If you play Smash Brothers seriously as a competitive game, the game itself has no future."
as a native speaker this is mistranslated. I havent looked at the rest but in this section he says something more like this:
Mmm. Personally, I sometimes feel that if you are the type that enjoys competitive fighting games , there are other competitive fighting games that are more suited to that. If you play Smash Brothers ONLY as a competitive game, the game itself has no future.
He essentially goes on to say what we already know, that he wants the game to stay simple enough to allow new players to not get discouraged just because they lost and allow anyone to quickly pick up the controls and play. You can tell by the words he uses that its not that he doesnt see competitive smash as a complete no, but he does is essentially saying that there is no future to a SOLEY competitive smash game.
Id like to note that i grew up fluent in japanese, reading and writing. i went to sunday school until highschool and have maintained my native level freshmen in highschool equivalent japanese. This means i understand most conversation barring any highly advanced topics (politics, chemistry, etc) and i pick up on word usage and context