No kidding. They need to believe something is going to happen, or at least seriously entertain the idea before becoming amenable to it, and otherwise will bash or scoff at the notion.
Third parties? Gross, this is a Nintendo fighter. Oh, Snake is in? I WANT SONIC AND MEGA MAN AND GENO AND BOMBERMAN
Pac-Man? He's ok, but doesn't belong in Smash. Namco's on board? PAC-MAN NEEDS TO BE INCLUDED
Wii Fit Trainer in Smash? lol, what a joke. Get serious. OMG WII FIT TRAINER IS IN THAT'S SOOOOO UNIQUE AND CREATIVE
Rosalina? She's cool, but other characters should get in first. WOW ROSALINA WAS OBVIOUSLY THE BEST MARIO CHOICE
Gen VI Pokemon? Nah, there's no Lucario/Zoroark equivalent. Pass. Oh, Greninja got included? WELL EVERYONE WANTED AND PREDICTED A GEN VI ANYWAY
Rhythm Heaven? Nah, that series doesn't have any playable potential. Oh, Chorus Men were leaked? THAT'S SUCH A GREAT CHOICE
Chrom? No way, he's so boring. He got leaked? I CAN'T WAIT! Oh... he's not in the game? WAAAA, I WANTED CHROM!!
Shulk? Ehh, he's cool, he'd be interesting, but I don't know if he's the most likely choice. Oh, Gematsu is a thing? SHULK HAS BEEN OBVIOUS THIS WHOLE TIME
Duck Hunt Dog? Are you kidding? He has no moveset potential and barely anyone wants him. OMG DHD IS MY FAV NEWCOMER
Dark Pit in Smash? That's dumb. Oh, Dark Pit got included? That's dumb.