Something that baffles me, by the by:
Where did the stereotype that none of Geno's fans played SMRPG come from?
Yeah, I have seen a few Geno fans who never played the game, but most of the Geno fans I've met have played SMRPG... and many multiple times over. I feel part of it might be because of Rawest Forest being huge back in the day, but even so, the amount of Geno fans I've met who never played SMRPG and only saw Rawest Forest have actually been zero. Many younger people are Geno fans, and it's not because they saw him as a meme. I've met a lot of younger Geno fans who have played SMRPG, either on the Wii, Wii U, or SNES Classic (or, ahem, illegal means).
"But if they played SMRPG, they'd know that Mallow has way more personality and is VASTLY superior to Geno! Therefore, they never played SMRPG!"
That's some loudly shoehorned, faulty logic based solely on opinion while refusing to acknowledge that other opinions exist. On top of that, it's a massive generalization. Sometimes, people click with other characters than the ones other people did, yet a lack of personal attachment will logically make them feel like their opinion is the 'right' opinion... when it isn't. There is no 'right' opinion and making a solid argument on subjectivity will never work. You can't have a solid foundation on a ground made of gelatin. Saying that people who like Geno didn't play SMRPG because Mallow is better is such a long reach that Mallow's stretchy, noodly arms wouldn't be able to manage it. I've seen people who found Mallow irritating (and while that baffles me, who am I to say that their opinion is wrong when it is subjective?) and loved Geno. I've seen people who hated Geno and adored Mallow. I've seen people who love both equally (hi, I'm in this camp).
Geno's fans don't just exist in a vacuum isolated from anything else SMRPG-related. The subset of the fan base is not the entirety of it.
In fact, I think Geno has just as much personality as Mallow. Mallow is a little ditzy, but he's a tough cookie and calls it like it is. He is emotionally sensitive and does have a tendency to cry, but especially given his situation, it's understandable. He's also a very nice and helpful fellow, resilient and trying his best to grow and figure out his place in life. Geno is wise and clever, but he isn't just a perfect star. He's loyal and attached to his duty, yes, but he doesn't behave as one would expect of a heavenly being. He sasses Bowyer and tells him to
chill out, and when things look grim, he ends up cowering (again, Bowyer situation). He's also expressive and jovial and full of laughter. While patient, he does have a bit of a temper (see: trying to leave Star Hill without the star piece, wherein he gets freaking huffy and FURIOUS, determined to the point of even looking a bit unhinged). He's a protective soul, even of people he hardly knows (see, Mario and Mallow in the intro in Forest Maze, wherein Geno protects these two people who may as well still be strangers). He's also incredible with kids like Gaz.
Just because a character is calm, collected, and is able to compose himself, it does not mean the character is automatically 'boring'. The people who actually played the game would know that, after all, for Geno is actually very expressive and has moments where his personality shines through. You can't get that out of just skimming a script online and ctrl-F'ing Geno's lines. In fact, given that is rooted firmer in logic born from in-game evidence versus online documentation, that is far less a reach than the, "The people who played the game would know Mallow is better," argument. It's objective that he's more expressive than you'd see if you just read the script. It is, however, subjective whether or not you think Geno's character was handled well. After all, do I think his potential was largely understated and that he could have been written better? HELL yes I do. I really do agree. Mallow's personality shines through better than Geno's. However, I'd call this a flaw in the writing (especially with RPGs still being in their infancy and this being the first Mario RPG ever), not a flaw in the character. Geno is not a bad character; he could have been written better.
Of course, I feel only people who actually played the game and had an open mind would understand the level of subjectivity and understanding here, but alas, here we are. Not everything is black and white, but a loud portion of Smash fandom certainly doesn't understand that.
What I'm saying is Geno and Mallow are both good and valid characters and you can't dislike a cute star that likes ducks