Stopping a penalty is incredibly difficult for a keeper. You have to stay on the line, and most of the times the ball is shot with such speed it's impossible to think,react and and move in the split second it takes for a ball to reach the goal line. Only if the keeper can be trained and instructed before a game (Krul) on how the opponents take their penalties, you stand a little bit better chance. Upper left and right corners in the goal are impossible to reach in a penalty even if you're 6 foot 2. You have 0 time to take the extra step it takes to reach. Lower left and right corners are tough to get to because it just takes too long to dive sideways and land in front of the ball.
All that aside, the Dutch at least tried to attack, even with 9 argentinian defenders on the goalline and Messi taking a stroll on the other half of the field praying for a counter. Halfway through the second half you saw argentina digging in, and wait it out for penalties. Heck their players couldn't even fucking steal the ball from Cilessen. Good job Orange, sad to see you guys not getting what you deserved.