Personally, I've found I like playing guys who taunt at the start. It's usually a sign they tend to be more of the 'I'm gonna relax and have fun' type of players more than the 'I'm gonna have to win' players. Which I find more fun to play with in general as they'll switch characters and we'll do silly things in the match because of it.
Honestly, this cocky, arrogant "I'm better than you" attitude is much more pervasive than just FG. Go to Youtube. Been watching smash videos? Good, now look at the welcome page. Of the combo videos and exhibitions how many are titled nonsense like "Undefeatable: For Glory" or consist of making fun of the other players. It's a whole (sub?) culture that has emerged. Supposedly, Japan doesn't have this problem. It's all on us.
Of course, to be fair, this is a far bigger problem than Smash, or the even FGC. Spend an hour on League of Legends or watch half an hour of videos from Call of Duty and you'll find online gaming seems to be infected with a general malaise of bullying, immaturity and hate. If anything, the fact people think smash is a 'kiddy game' has made it better than the average as a lot of the little kids who think acting like rascist pricks will make them look older stay away.
Considering the great pains it seems they took with regards to player communication (e.g. no mic chat in FG, no messaging between players, etc) I'm amazed they let it stay around at all. Personally, I'd like Nintendo to take a stand and either make communication easier or just impossible. Are you trying to shelter people's kids or not? Currently we have just enough space for people to be bullies but not enough to have any interesting conversations. Make up your mind.