#FE is the perfect example for how "only the gameplay needs to be good for a game to be good" is a false statement.
Your gameplay can be fine but if the context and setting for your gameplay isn't appropriate then people won't like it.
So here's a small question.
What do you think are true issues with this community as a whole when it comes to stuff like speculation? I mean this in the vein of selection bias, echo chambers where only few characters are deemed acceptable and/or likely, etc.
The main issue is the fact that Smash isn't just a game Nintendo fans play anymore. It has it's own fan base that exists in it's own little bubble.
As a result, there is a difference between Smash fans and Nintendo fans now. Smash fans who speculate on characters only base it on what they see within the Smash fan base most of the time. That's why your K.Rools and Ridleys are perceived as the most popular choices within the Smash fan base, but ultimately aren't that popular on a global level among anyone who likes Nintendo games and plays Smash for that. Then when a character who is genuinely popular on a global level among Nintendo fans gets in, the Smash fan base throws a tantrum about how Sakurai never listens. Rosalina remains the best example of this. She was moderately requested within the Smash fan base but didn't really make waves. But she's one of Nintendo's most popular characters, if not the most popular Nintendo character, that doesn't come from the classic Nintendo era (the only characters that are comparable are Inklings and even they will need a few more years to catch up especially since they debuted on the Wii U. Oh and maybe Lucario and Isabelle, they are similar to Rosalina in this aspect, actually). So her inclusion is in actuality, a no-brainer.
But because the Smash fan base was stuck in their bubble, they threw a tantrum about it and then the "Nintendo's Lightning" meme was literally born the day Rosalina was announced for Smash.
I could mention a bunch more issues with the Smash fan base. But they may be a bit more subjective and may even offend some people. But this is the one thing I think we can all agree on. Smash fans and Nintendo fans are no longer the same thing.