You're getting a bit defensive, it really isn't much of a criticism and it isn't unjustified to say Messi hasn't shown his peak form at this World Cup. I'm not sure why it's so hard for some people to accept, it's weird, it tends to be the Messi fans as well which is ironic as you think they would have the awareness to recognise he can play better than this.
I know football is a team game.. But firstly the best player and sides playmaker carries a significant part of the burden for making the team tick. Secondly I'm actually talking about Messi's performances, not Argentina's. Argentina don't have to thrash every team 4-0 for Messi to play the perfect football he's shown before. Di Maria having a poor tournament isn't responsible for Messi not being as explosive as he used to be or his decline in dribbling. At his best a few years ago he was by far the best dribbler I've ever watched, by an absolute distance, he would skip around players as if they weren't there due to that combination of ball control and agility. If you think this is the best Messi can do then fair enough, but I think you underestimate what he's capable off.