Ryu was from a fighting game. Whether or not Ryu wasn't good in Street Fighter doesn't matter when he was from the ground up made to emulate his Street Fighter self meaning almost everything he had from Street Fighter was made available in Smash. That means all the light, medium, and heavy moves, the ability to anti-air with Shoryuken, the idea of stage control with Hadouken unlike the fumbling of all projectiles in Smash, and staple combos like cr. LK to Hadouken were all available to him. It would be insane if Ryu was a bad character and it might even anger not just Street Fighter fans, but Smash and maybe the entire fighting game community to see Ryu be bad in Smash. If Cloud, Snake, or Sonic were bad? Eh, people could give it a pass saying they don't really work in Smash, they couldn't or didn't know how to design them without breaking the game - case in point, Buster Sword's size which Smash makes closer to FFVII instead of Dissidia where Cloud would have outranged Shulk - or whatever reasons there are, but Ryu? Everything about Ryu is right there; Capcom, Street Fighter itself, and the community.