SMASH IS DIFFERENT, it's a fanservice game, you're supposed to please the fans on a fanservice game...and can you tell me who would feel alienated if Sakurai added Mewtwo, K.Rool and Ridley? I'm willing to bet the ratio of people who wouldn't like that would be like 1 to 20...he would finally throw a bone to fanbases that have been left unnatended because he was too busy porting everything from Kid Icarus Uprising to bother thinking about those fanbases.
Make Ridley, K.Rool, Mewtwo, Isaac playable? Probably 2% of the fanbase won't like them.
Make Rosalina, Duck Hunt Dog, Greninja, Robin, Dr. Mario, Dark Pit, Lucina, Wii Fit Trainer playable? Like 80% of the fanbase hates those characters, or at least one of them (This coming from a gigantic Rosalina fan...I just know she's not really an All-Star).
So why? Why did he do it? Seriously, by looking at Sakurai's choices and patterns, it seems more and more like he focused on doing the EXACT OPPOSITE of what the fanbase expected, but much more importantly, WANTED.
The only characters I think could be considered blatant fan-pandering would be Geno or Roy, Geno because he has no place among Nintendo All-Stars and appeared on one non-main-series game. And Roy because his fan-demand comes from Super Smash Bros. Melee rather than his own damn game. I'm actually glad Mewtwo sucks on Melee, because it helps prove that the fanbase wants him back not because of his moveset, not because he was in Melee, but because he's ****ING MEWTWO.
If he was making, say, Kid Icarus Uprising 2, then yes, let the man do whatever he wants and experiment as much as he wants, because he's dealing with a franchise that he revived and knows better, but if you're given the responsibility of making a game featuring Nintendo's All-Stars, you just CAN'T have favorites, you gotta listen to the fans because this game's supposed to be a love letter to all Nintendo fans, not a love letter to Sakurai, and if the fans want Ridley, K.Rool and Mewtwo, then give them friggin Ridley, K.Rool and Mewtwo before you start looking around your Top 10 games list to add characters.