Whoa, you guys need to slow down for a minute, because you are missing a key issue here: individuality. Uniqueness, if you will, something that people are running over one another to grasp a hold of nowadays.
Yes, there are only so many ways you can use a sword, and while Sakurai did admit Brawlers can be a bit generic as well, there are more ways for you to attack someone with your body than with a sword: close-fist attacks, open-hand attacks, multitudes of kicks, headbutts, shoulder-checks, shoulder charge, running attacks, elbow attacks, knees, grappling and throws, etc etc etc. The only reason Sakurai finds this to be a bit generic is that most of the characters in Smash use hand-to-hand combat and he's gone through a lot of what is available...but with a sword user? You swipe your sword in different directions and you stab with it, anything else is either flourish (like parrying, jabbing them with the hilt, etc) and would be based off character experience and personality or requires a bigger or smaller sword (fencing, two-handed, etc). Being focused on a sword is way more limited in terms of moveset, but the idea in RL is that you now have the advantage of wielding a weapon that can kill with a single strike instead of dealing blunt damage with your body...that doesn't really translate into Smash though.
Robin was a combo of both limited magic usage and wielding a sword a smidge differently from the others. Shulk was our first Xenoblade rep and he brought something new to the table: augmenting his base moveset with temporary buffs. Cloud was highly requested and brought us something unique: having a bigger sword (so more range and damage) but still being rather nimble (unlike Ike) while also having a projectile and a unique meter that enhances his specials and gives him a brand new one that is very strong. Corrin was also unique: having a pinning mechanic and even more range, having a projectile unlike and any other swordwielder before him/her, and having the Dragonblood powers to have unique normals and aerials unlike other swordwielders.
Now you are trying to say that 'there cannot be hate for swordwielders because people want X character and they wield a sword, so...' and that would be a sound argument...until you look at the requested characters.
I know little about Rex or XBC2 but I did see some gameplay when they focused on it for forever at an Nintendo Treehouse on the E3 showfloor one year, and from what I recall I believe Rex has a lot of unique spells or physical arts to pull from, as well as possibly having him use different Blades. I also haven't played Golden Sun, but I can tell you right now from what I've heard from our brothers of other mothers in the Isaac support thread that he is very unique. Isaac is a Venus Adept, which comes with a whole slew of spells and abilities, and his AT doesn't even have him attack with his sword and only has him use one of his many powers at his disposal, meaning that Isaac has plenty of room to be unique. Lloyd Irving from the Tales Of would also be unique, as he apparently can perform berserker feats and he dualwields, which is something new to Smash I believe.
Now, I've played the majority of the KH games, certainly each any every one with Sora in it, so let me tell you that not a single person who complains about swordwielders can complain about Sora...the dude is absolutely nuts! Even in his younger, less crazy days in KH1 he was still a bit of a combat acrobat. Back then he had offensive and defensive magic as well as utility with Cure and Stop, physical and magical arts with Sonic Blade, Zantetsuken, Strike Raid, Ars Arcanum and my fav Ragnarok. He can jump pretty high, glide around, and already has a dodge roll, and then he could also summon aid from others with his Summonings. Entering KH2 and he just gets more to work with: he gets more combo finishers that explode with magical energy and are AoE, he can stay in the air for a long time simply by attacking and leaving damaging trails of magical essence from his attacks, gains access to more kinds of magic, different Summons, and then he also gets access to Drive forms which completely change up his fighting style. He can become more magic and projectile based, more physical and combo based and fight with two keyblades, and in his Final Form he can control keyblades magically and have them attack at his will with ridiculous attacks. In DDD they introduce flowmotion, which allows him to do crazy spinning attacks and dash far and basically just do crazy magical parkour movement and attacks, and in KH3 he can transform his keyblades into different forms to attack with different weapons with different properties as well as using the shotlock which allows him to unleash an attack that has invulnerability during it's duration and is more effective the longer his focuses on the enemy. He can also use this for Air Stepping which allows him to move through falling debris and other difficult terrain extremely fast as well as close in on an enemy and barrage them, and of course he gains access to different kinds of magic and summons here too.
See, these characters are requested because they are loved AND they have the opportunity to bring crazy unique things to Smash. You know who isn't requested nearly as much and doesn't have anything super crazy to bring to Smash? Erdrick. He's just your average JRPG protag with average moves from what I have gathered. People argue he can use other tools like boomerangs...but Link does that. People argue he can use magic, but Robin does that already and the other above have more unique uses of magic or abilities than Erdrick. Being short and fast would be nothing new, and if they put him in armor and made him a heavy hitter we already have Ike and now partially Ganondorf.
What could Erdrick truly bring that would make him unique enough to outweigh the outcry of his inclusion being so un-requested and unknown in the West?
Hmm, I'm hoping there is some truth to this, mainly so we can see Erdrick's chances fade into nothing. I get a few groups of people really want him, but he really would be one of the worst choices to pick for so many reasons. Nintendo needs to keep on the ball with Smash.