I'm still trying to figure out the logic behind giving the golden ball to Messi. I know that Maradona was most probably right when he says that it was for marketing reasons, but I'll still try to find sporting reasons.
It's true that no attacking player, at least from the 4 semifinalists, was that much superior to feel robbed when Messi got the trophy. James' handicap was that he played only 5 matches, so he was rightfully not considered. The other potential candidates who play attack or as attacking midfielders were Muller, Robben and Neymar. The German scored 5 and assisted 3. Only 1 goal and 2 assists in the knockouts for him. Robben had 0 goals and 0 assists in the knockouts, but he did win 2 penalties, one of which was decisive. Neymar played only 2 knockout matches in which he registered an assist. Messi played 450 minutes in the knockouts (4 matches, but due to 3 extra times that's equivalent to 5 matches) in which he managed only 1 assist, while in most of the matches he was easily stopped and with 71 lost ball (10 per match) was the 2nd most dispossessed player. As it can be seen, neither of the three was good in the knockouts, but the numbers (overall and solely knockouts) support Muller, who happened to play for the WC winning team, unlike the others. Hell, Schurrle scored 3 goals in the knockouts and assisted the WC winning goal, while Messi, Neymar and Robben together have 0 goals and 2 assists.
So, even if only attacking players are considered, it should have been Muller. More goals and more assists than the others, and he also won the WC with his team.
But why only attacking players? Argentina had a 2:1 goal difference in those 4 knockout matches and Mascherano had world class performances in all of them. Or if we're looking for a WC winner - Schweinsteiger, Hummels and Neuer were brilliant. The German midfield won every battle, while the defense kept 4 clean sheets, and on two other matches they allowed a goal only when the match was already won.
I guess they will go with: "Messi was the reason Argentina made it to the final", but to say that, Messi should have been assisting or scoring vital goals on route to the final, which he didn't really do past the group stage in possibly the weakest group in the WC. It was the goalkeeper, the defense and the dm that took the Argies so far.
No sporting reasons whatsoever for this.