Bowser's personality of a somewhat goofy, comical foe isn't really expressed in his Smash moveset at all. They really don't need to give Ridley a personality beyond "fierce dragon", i.e. the one he already has, in order to make him work.
Bowser: Truth, but it's still there, so anyone with even basic knowledge of Bowser will recognize that. Simultaneously, Bowser is "the Nintendo bad guy," so leaving him out is kinda not an option. Unfortunately, he does compete with Ridley for the snarling beast spot, so even if Bowser had a personality as basic/mindles as Ridley does in the Metroid
games he'd still almost be necessary due to who he is. His new posture sheds hope for Ridley, though, because it's a bit more silly.
Ridley: That's a perfect personality: For an assist trophy or boss. Not a "character." Not someone you play as. It's like playing as an octorok.
...The non human character's have more personality. Look at sonic, for instance, he's all about speed and that's good. Compare that to captain falcon, and tell me who has more personality. Ridley has more personality most of the roster.
"Humanoid." Sonic is definitely anthro.
Ridley's personality is perfect for an AT or boss, but not as someone you "play as."
yeah cause Mario, Link and Samus have so much personality right. Ridley does have a personality. it's being a sadistic A**hole. not that personality really matters in Smash.
Mario: absolutely. Hoo-hoo! -falls asleep and starts snoozing-
Link: Yes, but more importantly, Link is "The second Nintendo icon," behind the Mario bros. Links falling screams in the N64 games are also much more relate-able than any snarl Ridley could throw out. Plus, human.
Samus: Not much, but this is where human is a benefit. When Samus does her taunt, you can easily imagine her just sitting there thinking something along the lines of, "Alright!" samus was already cemented as a playable character, too.
Ridley's personality up-front (in the games even if digging) is "a snarling beast," no different from any octorok or redead. Sure, it's a "personality," but it's not something any human can relate to, almost as if he only works on bare instincts. And yes, personality matters in smash, where you "play" as a "character."
Excpet Ridley does have personality. Ridley isn't just some snarling beat people misinterpet him as. He shows inteligience and allot of it. He is also the leader of the Space Pirates, if he was jsut some snarling beast do you think he would be able to control and lead the space pirates? His personality is being a cruel monster (Not monster as in species but monster as in how you would describe certain human beings) yes despite the curelity he is also quite intelect. But I'm not able to explain welle nough so jsut read this small thing
http://metroid.wikia.com/wiki/Ridley#Personality_and_traits. Peronality is already there, they just have to get it to work in the game.
And there is an actual valid arguemtn as to why Ridley might not get in. But most people against Ridley seem to be to dumb to realize it. .-.
I was actually aware of his manga development before your post, but I've always viewed that as having to go far too far for a video game character, and view it as irrelevant to a video game about video game characters. As canon as his mangas may be, this is Super Smash Bros, not Super Manga Bros.
And also, this is a game where you want to get as broad an audience as possible, and having to dig very deep, so far that you get out of video game territory, to get Ridley's personality, just isn't very good for him.