If you can't argue with someone in a civil manner, you can always put them on your ignore list, or just choose not to respond to them. There's no reason to be rude over a conversation about modes in a video game, of all things.
On the topic of Smash speculation, whenever we get a Smash announcement, I wonder what newcomer(s) will be announced alongside the game. I can't think of any really obvious picks like Inkling or Bowser, or characters that people had wanted to see for a while like Meta Knight, Pit, Mega Man, or Wario. (maybe Geno, but I'm not sure if he'd be the type of character to be revealed when the game is first announced; I could be wrong, though)