What specials possibly require 11 inputs? The only moves I can think of in any fighter are like, KoF Pretzel, which is a super, not a special move.
It isn't the number or complexity of inputs but the timing in executing them that anyone has problems with in Smash. The game is accessible and that has never been a problem, but the tech ceiling is quite large. Some complex things in Smash look a lot less complex if you jsut think about number of inputs, but the precision in them is large. Shine Bair? Literally just Down+B, Backward, Up, C-stick bair. 5 inputs. In execution though there is a lot of room for error in both timing and input. RBR's/Wavebouncing, same thing, you just do a reverse neutral B (Back, B) and then a B-Reversal (Back relative to where you face now) 3 inputs, with a huge margin of error to accidentally use a side B or miss the window to B-reversal.
The simplicity of Smash's inputs actually causes a bit of input error since a lot of simple things are similar in input due to the analog nature of the game.
Not that that's a bad thing, games shouldn't be easy to reach high level in, but to say Smash has easy inputs ignores a lot of the game's mechanics.