Problem with his arguments are, and I hate to say this, that he doesn't get Ridley's character.
I appreciate him trying to knock down the NES excuse, because it isn't valid, though he doesn't do it properly, the reason the NES appearance is invalid isn't because of technical limitations or that it's only 1 out of 8 Metroid games he's in, it's because it's been retconned with Zero Mission. So yeah, even when he knocks down the invalid arguments it doesn't work, because he's doing it wrong.
Okay, so we move onto the next thing, and that's his reasoning for that Olimar and Bowser can be shrunken down, and Ridley can't. Again, he flops a counterargument with Bowser. It's perfectly viable for Bowser to be shrinken down because in spin-off games like Mario Kart he's already getting shrinken down, and then there's Super Mario Bros 1 and 3 too, both when remade still made him the same size. But no, his argument is that he's a turtle. Then there's the Olimar thing, and yeah I'll give him that, fair argument, however, Olimar still serves as a good argument for Ridley supporters.
You see, and this is where I'm getting at, Olimar's game and character is mostly about being small. Being in this big world where everyday objects suddenly are massive, that's part of the appeal of Pikmin. Is Ridley's size part of his appeal? Sure, but a very small part of it. Ridley's character isn't about being big, I don't know when people began believing this, but it isn't. A big thing about Olimar's character is that he's so small, and yet they had no problem resizing him. Ridley is Samus' archnemesis, just like Bowser is Mario's, Ganondorf is Link's and Wolf is Fox's. That's Ridley's role, his role isn't to solely be a big threatening dragon in the Metroid games, if you honestly believe that then I'm sorry, but you missed the point of Ridley's presence in every of those games. So again, I'm sorry, but the "he's a dragon, thus he can't be scaled down" argument is ****ing weak, because Ridley isn't just a generic big dragon, he's Samus' rival, he's incredibly intelligent and the head of the Space Pirates, that's his character, he isn't about being big. That's why Ridley can be resized and Kraid can't, because Kraid is only about being big. He has become as much a fan favorite for Metroid fans as Ganondorf has become for Zelda fans. He's no doubt one of the last Nintendo All-Stars that are missing from a playable role in the game.
As for the fan-made character models, have you seen how the majority of them handles his neck? That's why he looks out of place, they don't change the proportions as necessary or pose him accurately so he can look big while being small. Instead, they make him lean, pose his neck in a weird manner, and thus they're forced to make his head small and stuff like that. A professional team can scale proportions properly, one person working on a mod can't.
Plus, then there's of course a big thing I notice that nearly nobody takes into consideration. Why can Mario Kart resize Bowser and Petey Piranha? Why can Smash Bros resize Olimar? It's a spin-off series for christ's sake people, there's no such thing as canon, pretty much all Nintendo characters can and have been molded and shaped after which role they need to fill anyways, even Ridley is scaled down during the course of Metroid Prime 3, he's a lot smaller as Omega Ridley than as Meta Ridley in that game.