They do all this to force the referee to make decisions, with the hope that if he is confronted by imagined bloodshed often enough, he will ultimately determine he has seen some. Applying this sort of pressure on the official is a skill that, by their own admission, United States players generally perform poorly, if they perform it at all. ...
That idea, though, runs contrary to the ethos of idealized American sports. As Ramos said, American athletes are typically honest on the field, no doubt influenced by years of being told to be strong, battle through contact and finish the play. The tendency of American soccer players to eschew diving, Martino said, is directly related to the fact that diving is one of the things that soccer critics in the United States rail against so passionately.
“That cultural perception already handicaps the American player,” Martino said. ...
The best attackers in the world, including Cristiano Ronaldo and Luis Suárez, regularly fall to the ground, particularly if they feel that they are going to lose possession. And why not? If it works, they get a free kick. If it doesn’t, they were going to give up the ball anyway.
Call it cheating if you want, but having scruples can be costly. In England, for example, players have traditionally stayed upright, too, even though it has sometimes been to their detriment.
“The long refusal of English players to dive may have been an admirable cultural norm,” Simon Kuper wrote in his seminal book “Soccernomics,” but “they might have won more games if they had learned from Continental Europeans how to buy the odd penalty.”
--Sam Borden, NYT, on cultural uprightness