I think the only place where Pit could be easily gimped is below the platform, but odds are that he's never going to be there in the first place.
Even so, there's only a few characters that can actually gimp Pit well anywhere are those with a good long ranged and aimable projectile like the Link's or Yoshi, but easier said then done because have you tried hitting him in Freefall? Then you gotta follow it up, which is again easier said than done. Does this sound like a person who is easy to gimp? He's not just going to be floating there, begging for a Spike.
Also Yoshi is another character that is far from easy to gimp. First of all, Double Jump + AirDodge = Zelda's UpB Look Alike. You are talking about something that sends someone the distance of about 6 Blocks, INVINCIBLE. You know what Invincible means? It means you can't hit him! How can you gimp him if you can't hit him? Also, the entire Footstool thing is impossible to do anyways. First of all, it only works if he's doing nothing. It can't cancel out an action. Basically if you try to do this stupid thing, then He'll just blow right past you with an Airdodge, or you'll just eat a rising Uair to the face, possibly into a stage spike. Basically, if you do Footstool him by just jumping at him, then jumping off of him, then he deserved to be footstooled in the first place