Well, that´s another point, there´s a difference between "special skills don´t affect anything" or "they don´t affect that what Konami says".
I think the dribble special ability influences the commonness of dribbling, but because even players without this special skill dribble very often you can´t see it clearly.
Just an advice from me if you don´t believe that the special skills have an effect on the game:
Take a team and set all abilities from the starting players to 70-80, but deactivate all special skills, set form arrows to green for your team and play a few matches on 4* or 5*. Then go to edit mode and assign some special skills for the same team, eg playmaking, direct play and assists for the midfielders, def. control and man marking to the defenders, reaction for the strikers. And then play with the same conditions against the same team and you´ll see the difference.