Not for SSB4, I'm talking about his wings within the confines of the 2D games. Kind of OT for this thread, but whatever. Ridley's always had some major advantages over the player in a platforming, contact-hurts environment:
- Floor-sweeping projectiles
- The tail swipe
- Grabbing the player
- Extreme mobility compared to the other bosses
Now, something like Yakuza (spider asshole in Fusion) is a different case because they were making you fight the embodiment of the Space Jump, but the Super Metroid fight is specifically designed to emphasize verticality. You've acquired the Space Jump and the creators want you to use it in order to get the jump on Ridley, avoiding his projectiles and raining down Super Missiles on him. In the Zero Mission fight, while the arena is a little wider, having larger wings would make it difficult to attack him from behind, meaning you wouldn't have an easy "out" from avoiding his tail swipe and claw-grab attacks. Notice that in Super, Ridley's hunched position, even when roaring, is vertical and rectangular, just like the arena you're fighting him in. Enlarging the wings would break that, because you're essentially playing Pong on steroids in this case, but going around him repeatedly instead of side-to-side.
Now, in a "pitfalls kill" environment like in Smash in contrast to a "touching things hurts" environment like in Metroid, Ridley's wings work way better being larger, because you don't necessarily have to worry about losing vital health, and on top of that Ridley doesn't have to occupy the same platform as you. Brawl handled it well with a variety of platform and aerial attacks, including flapping up winds to try and push you off the platform, which is much better-suited for Smash's "edges kill you" environment.