Ridley was the the driving force in Metroid Prime, if Ridley and Samus hadn't encountered eachother, Samus wouldn't have gone to Tallon IV and accidentally discover the Phazon stuff
She went there because of a distress signal from an unknown source, it just so happened that Meta Ridley was there.
Any other pirate could have accomplished the same thing. And while he does serve as motivation for Samus personally,
the plot quickly shifts focus away from him until near the very end of the game, where players have most likely forgotten about
him. He's more of a convenient excuse for Samus to do stuff that doesn't involve the Federation. And it's not like he's the one who
brought the Pirates to Tallon IV, since he was kind of too busy being operated on.
Incredible insight here, thank you for pointing this out
However, I'd argue there is a middle ground between needing legs, and copying DK's kick, when Ridley has a tail and wings to use
Ridley uses pretty much every part of his body in his attacks.
Head: Jab finisher
Mouth: Dash attack
Claws: Jab combo, side b
Feet: Bair, up smash?
Wings: utilt, uair, dsmash, up b
Tail: everything else except neutral b, dair and fsmash
It's also worth noting that he used to do his grappling with his feet in Super.
Actually it was kinda stupid for Ridley to lead Samus straight to the space pirate phazon research. Although maybe for the best. He was still freshly revived and likely couldn't escape the gun ship in deep space.
Honestly, Ridley probably doesn't really care if the Pirates succeed in their goals or not. Their science stuff probably flies over his head
(he's cunning, but not BRILLIANT) and most likely isn't part of High Command. He only takes part as their military commander to indulge
his murderous tendencies.