It's not even a matter of characters being bad. What you're talking about is bad execution. I'm talking about bad design. Bad moveset concepts. Not only did Sm4sh got execution wrong, it also completely butchered every character's concept design by making everyone do exactly the same things. We have a roster of 51 characters that are all basically the same.
In Sm4sh there's two types of characters. Those who grab you and then chain the same aerial attack 3 times, or those who have ONE special move that basically centralizes their whole moveset around it, with no unique or interesting individual qualities to them.
Zelda is the symbol of bad moveset concept. Her design is to be this really precise character that is extremely volatile when things are messed with like increased landing lag on really precise Fair and Bair which renders her without a way to approach in the air or do much in the air other than try to catch someone with Nayru's Love. Staying true to the series? Give me a freaking break. Nothing Zelda does actually stays freaking true to the series in Smash with Farore's Wind being close. Staying true to the series actually hurts her more than it helps since it makes her so limited, but then you look at characters like Wolf and even Pit.
Sakurai's faith in old fans or catering to old fans already killed several characters: Falco, Ganondorf, Toon Link, Samus, Mewtwo, Zelda, and I would even argue Pit and Palutena not to mention Dark Pit and Lucina are screwed over because of this stupid need to stay true to their "original" designs. There is nothing that suggests Falco jumps high since birds can't really jump high. The fact he was a clone in Melee killed everything about him. Oh, but he's a semi-clone. Yes, a semi-clone of a character whose design was to be a rushdown character. Tweaks aren't going to fix Falco when stuff like **** air speed is set in stone. Ganondorf? Rumors of him using a sword in Melee, but they ran out of time? That's poor management and poor ethics. Look, I love games, but the gaming industry is a freaking sweatshop and it's not surprising that more and more games are getting glitchier, getting more DLC, and getting more stuff cut. Ganondorf can work as a slow and mighty warrior, but he does not have to be a semi-clone of Captain Falcon, tweaked a bit, to actually be that. Ganondorf's main issues right now are that without a safe way to deal with stuff at a range even with his massive natural range, he's screwed. He has to get in to do stuff or make people get into his zone to do stuff. If he had a sword like Ragnell, he wouldn't have to do that and could space well. Even if his projectile was slow as sin, he could at least have something to zone a bit like Falco, but have durability to back that up. Speaking of which, what the hell is Falco even supposed to be? It seems like he's a zoner in Melee and his gear made it look like he was an anti-zoner in Brawl and SSB4, but we all know what he was in Melee, Brawl, and SSB4. He played games his designs don't suggest.
Toon Link should have represented the other iconic Zelda gear regardless if they're from Wind Waker, A Link to the Past, or Oracle of Seasons; he could have been the Link who represented the 2D games while Link represented the 3D games. I mean, has anyone ever seen 2D Link use a Jump Attack? He had the stall and drop Down Thrust with the Roc's Cape, but never did a Jump Attack. Samus's at least has moves that are true to her series and works as intended, but there are some things that are just weird like Dtilt, Side Smash, Up Smash, Fair, and her rolls. Dear lord, her rolls are messed up. They're slow as sin and she can't even "crawl" which would her crouch way more useful. Maybe a dash like in Prime or Other M for dodging, replace Dtilt with Bombs, have Bombs be Super Bombs, y'know, a timed explosive that would be wicked even if they're not that practical. Oh, and speaking of practical, let's give a tall character an Up Smash that practically ignores everyone who's shorter than her which is like 60% of the cast. Should I go on?
It's bad everything. From giving characters the ability to stun and spam lasers, to an incredibly fast spike, really fast and powerful aerials, little to no end lag, useless moves like what the hell is Captain Falcon's Ftilt even there for when you have the godplayer jab? There's a way to make a game appeal to both casuals and able to be competitive and from what people have said about recent "fighters" like Smash 4 and Mortal Kombat X, they've failed horribly since they're spammy and certain characters just overpower everything. Superman in Injustice, anyone? I get it, Superman's all powerful, but in a fighting game, he doesn't need to be all powerful like that. There's a reason why Algol was banned in Soul Calibur IV and was nerfed to be a reasonable fighter in Soul Calibur V.
Oh, and there's a third type of character: characters that don't work. They're the characters so overshadowed that they could be removed right now and people would only complain about their removal with no legit argument for why they should be in the game. "Oh, Falco can edgeguard with Fair." Y'know who else can? EVERYONE. "But Marth has tippers!" SO DOES LINK AND PIT! EVEN SHEIK HAS SPACED HITS THAT ARE MORE POWERFUL!
Tbh the only characters I find to be interesting by design are Rosalina, Pac-Man, Shulk, Villager and Bowser. The rest are just carbon copies with different colors and different visuals. The only thing that differentiates characters is whether they're strong due to execution and frame data or not, and by now I've grown bored of this.
Add in Ganondorf, Mega Man, and Duck Hunt. Ganondorf literally plays the counter game that ironically, characters with counter don't. Little Mac is somewhat interesting, but when the game doesn't factor in input lag, he's really annoying. Mega Man being based on his own series which explains all the projectiles already sets him apart from everyone else and even if he's a ***** to fight, he's at least someone who doesn't bum rush you like Fox, Captain Falcon, Diddy, Meta Knight, Palutena, Sheik, and more. Duck Hunt and Pac-Man are the closest things we have to Snake who could lay traps, play incredible mindgames, and control the stage so interestingly. Oh, and there's Jigglypuff if you like dealing with a cloud that hovers and wants to murder you.
By design, at least Link, Toon Link, and Samus have their own, wall out game play, but it's at a point where it's annoying, so I don't give a damn.
Brawl was a terrible game due to its crappy mechanics, slow engine and a bunch of other problems, but at least the character design was great. Peach was unique, the ICs were unique, Zelda was unique, Ness was unique, Snake was SUPER unique, Olimar was unique, DDD was unique, Link was unique, even the three furries were unique when grouped together and in comparison to the rest of the cast. Characters actually felt different from each other, and you had to give some time to every character in order to find the potential of all of their tools.
In Sm4sh everyone does the same thing. Grab, d-throw, fair/nair/uair... and that's it. Sure, there are other moves and whatnot, but in general everyone is basically just the same thing.
That's why Sm4sh's design is bad, not because characters have dumb frame data or reach. It's because barely any character in this game has individuality.
Peach at least had a mechanic that set her apart from everyone else and even then, it doesn't take that to make a character unique. I mean, look at Little Mac and his mechanic which does nothing, but irritate people. The Ice Climbers are cool in concept, but the fact that nobody addressed their grab shenanigans is one thing that makes me hate them. I'm sure SSB4 would have, but we'll never know because the New 3DS wasn't released and adopted by everyone at the time and it still isn't adopted by everyone.
Tripping alone was stupid. Smash 4 is basically Brawl without tripping, edgehogging, chaingrabbing, and other dumb stuff like Falco's dumb*** lasers or Meta Knight being a poorly executed character. That alone makes Smash 4 better in a sense there's no dumb RNG unless you're playing Mr. Game & Watch and sort of Peach and Villager, but at least those weren't a universal and persistent problem because they were designs intended to make the characters unique in some way and not **** up everything.
If I had it my way, I would thoroughly go through every character and if that means the roster gets reduced to 25 characters because that meant too much time to work with everyone, then so be it. 50+ characters is a lot for game and for a fighting game, it's massive. It's no surprise that a lot of the characters do the same thing or similar things, but when it borderlines that it's character design like Fox and Falco, Link and Toon Link, Pit and Dark Pit, Marth and Lucina, and Captain Falcon and Ganondorf, it's at that point of why even bother adding so many characters if that means so much is diluted? This isn't Mario Kart where characters are just visual and audio representations and separated in weight classes or a freaking first-person shooter where appearances don't really matter except for camouflage which the game sometimes handles on it own.
If I could, I would make this game more like King of Fighters XIII which was balanced since you could use anyone, characters each had their own niche and there are about 30? characters, but I would have to make it easy to get into since KoF isn't exactly a pick up and play game. At the same time, I don't want Smash to become like Marvel vs. Capcom which with 3, is basically Melee or Brawl where there are select characters way too damned good.
Funny, I was thinking of doing an animation project by redrawing and redoing some of Falco's moveset just to test out gif making and stuff, but now that I look at it, I might destroy Falco's "beloved" moveset and make it actually different.