He doesn't need to star in a game(which he did, for the record, as Mario Party 3 and Dance Dance Revolution, his two story roles, are not sports games in any way) to be popular or have a cultural impact. People know him because he's that damn popular and showed up a lot. There was a ton of backlash for him not being in 7. That says a lot about his impact.
Though yeah, if you believe a character needs to star in their own game(Waluigi's major roles were not the true starring role) in a non-spin-off to get in, that's fair. But that doesn't mean people accept that as a good answer. If you apply that to every single character, which is the only reason it should be applied to Waluigi, a major Mario series character(just like Toad), you need to remove quite a few as is, especially if you consider when they were added; no Ganondorf, Bowser, Sheik(Zelda starred in a CD-i game), Jigglypuff, Pikachu(neither starred in games yet, though maybe it was Pokemon Yellow?), Falco, Wolf, Daisy... and I could go frankly on. It's an arbitrary reason that needs to be applicable to everyone first if you're going to seriously care about something as silly as "wasn't in a mainline game", which frankly is so beyond arbitrary it doesn't matter in the first place.
Waluigi is popular non-ironically. If he isn't playable, it's either Nintendo stopping Sakurai or being unable to make a really good moveset(Daisy had the Echo fighter going on more than anything. She has few stand out abilities anymore than Waluigi does, and he can swim in the air as is, plus is the original Mario Sports Character. Daisy was literally nothing more than a Peach recolor and had no differences till the spin-offs later added her flower abilities).
I'm not sure what the issue is, though? They're popular characters. Their fanbases get discussed.
I can see a case to ban discussion for the same reason we don't allow non-game 3rd party Support Threads(namely due to controversy), but if there's no case to be made, then it's frankly not worth worrying about. Let them discuss it in peace and be civil about it. Just like with any other character discussion.
It's not wrong at all. This is what I'm talking about. People harshly judging others for not fitting someone's arbitrary standard. No, there is not a problem with wanting a character unironically no matter if they're a game character or not.
