I know, I'm a bad person:

- third party, unfitting

- third party, unfitting, annoying moveset

- semiclone, better to be a costume

- annoying, bland, pointless, in the original game you kill the ducks, here the duck and the dog are friends?!?

- semiclone

- annoying and boring moveset, unimportant character

- boring moveset

- unimportant character ignoring the anime, kirby semiclone with less actual moves and more sleep gimmicks, improve Kirby instead

- annoying and boring moveset, bland character design, should have never been promoted to playable

- useless when you have Mewtwo, who's also more iconic

- clone

- yes I did it. Make it an alt of Mario like Louie is an alt of Olimar... unless you give him an original moveset based on Luigi's Mansion

- why there are 2 Marths?

- he's cool but I'd rather have no third parties

- I want Mii to be an unique not-customizable character with moves based on the Wii- games, not this unnecessary waste of development

- same

- same

- same as Megaman, I like him but I'd rather have no third parties

- makes sense in the roster but her moveset sucks

- why not simply an alt?

- no need to explain

- same as Daisy

- never liked this "character", it looks like a generic toy robot and I find its moveset not that much interesting
:ultrobin - I don't like his moveset, I prefer Corrin

- I choose to keep Marth, so, alt or out.

- unnecessary

- third party

- clone who could have easily been an alt. costume

- uninspired moveset, never liked it since Melee

- boring and unfitting... the monado arts gimmick is fun but the moveset sucks; despite being first party it feels like a third party character

- third party

- third party

- third party, never liked his moveset

- third party, while I like Sonic as a character, I absolutely hate how he has been represented in Smash

- I choose to keep Young Link because I like his design more, especially now that Link is from BOTW, Young is the more traditional one

- I like Wario, but I dislike this version of Wario

- I don't like her moveset, it's uninspired like Sheik but even more boring

- reserved slot for Bandana Waddle Dee/Waddle Dee in case he makes it in the roster
I finished...
37 cuts (possibly 38)
The remaining roster is:


































34 characters.
IMO a much better selection of iconic Nintendo characters without the unnecessary spam.
Luigi is not there but I explaiend, his actual semiclone moveset sucks, unless they give him the vacuum and the light.
Wario is excluded for a similar reason: give him a decent moveset, mostly based on the Warioland series, or keep him out from the roster.
I may add Palutena back the day when Sakurai will make a good moveset for her.
About Jigglypuff, I wouldn't mid if instead of just cutting her, she would be replaced by Meloetta instead... still a singer, but a more unique and interesting one IMO, especially because of the ability to switch between the two forms and fight while dancing (unique moveset potential).
Regardless of the cuts, this roster is still missing Classic Ganon to be a true Nintendo All Stars roster... it's the only important classic character who's missing (excluding Toad who's part of Peach).
Eventually, a last gen Pokèmon, since all the ones I kept in the roster are Gen 1 (not intentional though);
Honorable mentions who were considered for the cut:

- I'm not really fond of his moveset... but I'm ok kinda (also he's not that important as a character)

- not a big fan of his moveset as well

- he shouldn't be a clone, but he deserves to stay in the roster

- I don't like how he plays in Smash, but he deserves to stay

- same as Dedede

- same as Bowser Jr (minus the not important part) and Diddy

- semiclone kinda... though he's important for the franchise, and at least is more unique than Falco

- well, I wouldn't ever cut him, but he seriously needs to be decloned and use masks into his moveset