I actually mentioned Jigglypuff before. Ridley's playstyle would be so unique that the character it can best be compared to has a completely different playstyle overall. It's just the whole aerial combat thing that makes them comparable.
Ridley's like Bowser meets Jigglypuff, I guess.
You can talk all the possible movesets for Ridley all you want and no I'm not using the "slim hopes route" as you call it. It's just that the movesets you all are coming up with don't seem very likely. Ridley has tremendous power so him being weak on the ground make little to no sense especially considering the fact that in Other M he fights you while crawling on the ground and that was still very effective. Also, the notion of Ridley being able to fly while other characters who also have wings no longer have flying in their movesets as shown by Pits change seems HIGHLY unlikely.
That's just Pit. And if you've played Uprising, Pit can't fly anyway.
And sometimes Sakurai needs to change canon to make things work. For Ridley, this would mean resizing him and merging him in the ground (Ridley will be aerial based, even if he cannot fly). Even though he can fight on the ground in Other M I don't think it's absolutely necessary to make him powerful on the ground in game either.
It's not that he's weak in the ground though, he's just really really slow.