Had a good chat about this with a friend who was semi-professional footballer.
Anyway, the conclusion I made was that a lot of work done managers are not done behind the closed doors in training and other preparations regarding the game. Of course we fans only see team selections, substitutions and some ranting down the sidelines, which are obviously important part of game, but it seems hard to judge managers fairly purely based on these attributes.
Personally, I think Pekerman is an outstanding manager in constructing a team that understands each other so well, and capable of playing some brilliant football.
Playing football is just more than selecting best players, setting formations & tactics, and click play, as in Championship Manager. It requires understanding player's mental psyche, physical condition, and the chemistry within the team in general. Obviously I agree with Denco in that Pekerman has made some absurd decisions such as decision to exclude Zanetti & Samuel (Coloccini, Heinze, Scaloni were crap in the WC) and some stupid substitutions, but ignoring these I think he did a good job.
BTW, I think Zac & Capello are two most overrated coach in the world. These guys are tactically clever but have absolutely no flexibility in dealing with personnel. I was estatic when Deschamp was announced as the next coach just because that meant I didnt had to endure Zac era.