and sakurai made that excuse, remember that nintendoge pic where he said size didn't matter? Ridley actually has been a bit larger than Samus but not too big in the Metroid series, but typically today Ridley is a extremely large character.
Doesn't matter if it won't feel like the characters origin, Captain Falcon doesn't really do any of his moves in F-Zero
Falcon didn't have a defined origin then. All we knew was he was from Port Town and that he drove the Blue Falcon. They could do whatever they wanted with him.
Ridley, on the other hand, has a defined origin: He's a big, scary, space pirate dragon that killed Samus' parents.
Not only does shrinking Ridley feel uncomfortable, but he's no longer intimidating or terrifying, and he has no real way to show off his flight capabilities.
Sakurai also said that what determines a character being playable isn't their popularity; it's their uniqueness. You can't just slap a moveset onto a character and call it a day. It has to feel like that character. It has to define that character. And since Ridley is a big, scary space dragon, making him small literally only leaves the "space" part. And that just describes where he's from!
I personally feel that they can't shrink Ridley down any more than they did in the Wii U version and for it to not look wrong. It could fly in the NES game since that design didn't really represent Ridley, but it can't work anymore.
If a future Metroid game redefines Ridley, then who knows? Maybe he could work. But he can't yet.