You're heavily exaggerating Waluigi's potential did you know that?
Not really. Considering that he has random over the top abilities within the series he hails from, having more made just for Smash isn't so strange. I hate using the term "blank canvas", but it's kind of what Waluigi is.
Remember how Sakurai only counted Animal Crossing and Pikmin as the only new franchises worthy of having characters in Brawl? Well, it turns out that those two along with Nintendogs, Big Brain Academy, and Wii Sports are the only new franchises created by Nintendo EAD between Melee and Brawl. As for the retro franchises, Nazo no Murasame Jou (Tamakaru's game) and Mole Mania (Muddy Mole's game) were made by Nintendo EAD. That's pretty much it.
Remember how I confirmed that to be
false quite a while ago?
He didn't say that they were the only ones "worthy". That was a mistranslation.
What he ACTUALLY SAID was that there weren't any series after Pikmin that had a character suitable as a playable fighter.
Remember how Sakurai considered Balloon Fighter, Bubbles, Excitebiker, and Urban Champion before he picked Ice Climbers for Melee? Well, it turns out that Balloon Fight, Clu Clu Land, Excitebike, and Urban Champion are NES games developed by R&D1. Other games developed by R&D1 are Devil World, Duck Hunt
, For the Frog the Bell Tolls, Gumshoe, Hogan's Alley, Sheriff
, Wario's Woods
, Wild Gunman, and Wrecking Crew.
Except that those were merely made up excuses as to why the Ice Climbers were the best choice other than stating the obvious: they were picked to incorporate a gimmick.
There is no indication that Sakurai
seriously considered Balloon Fighter, Bubbles, Excitebiker, or Urban Champion. What he said in the Ice Climbers' page in Melee was that he made a list of possible options for an NES character, and put them all through a process of elimination, giving the four mentioned as examples while stating that the Ice Climbers had no such issue.
In fact, going by what Sakurai said about the character
he wanted to see most in "Smash 2", one would think that he'd consider
Mach Rider before seriously considering any of them.
If Sakurai did not add popular second-party Nintendo characters like Isaac and Saki over less popular first-party Nintendo characters like R.O.B. and Zero Suit Samus in Brawl, why would Sakurai add a popular second-party Mario character like Waluigi over less popular first-party Mario character like Toad or Bowser Jr. in SSB4?
I'm going to have to stop you there.
The character roster lineup was "finalized" by July 2005 with the sole exception of Sonic, added in early 2007. Saki's popularity in Japan for Brawl didn't really come until
after then. Hence why Sakurai said he "did what he could to include him" by making him an Assist.
Isaac and the Golden Sun series as a whole was not really popular in Japan, and Isaac's requests for Brawl, like Saki's, were
after the roster had been finalized.
Sakurai would have no reason to include either of them back when he was deciding characters.
And since you're inevitably going to counter about Zero Suit Samus and R.O.B., Zamus was added because Sakurai wanted to give Metroid another character (and had no reason to believe Ridley was a decent option at the time given that like Saki and Isaac, he would not see Ridley's popularity until later), and R.O.B. is pretty damn historic to Nintendo.
