Diving is basically cheating, and is a big part of the reason Americans can't get behind the sport. In real football, guys basically have to lose body parts before they'll fall down, and even then they have to be coerced to stay down while the medic does his job. And a player going out on a boddy board is serious, life threatening business.
In soccer, it's a ploy to ice the game, cool a player on a tear for the goal, or eat up time that they may get back after the game officially ends or to force a shootout etc.
Finding loopholes in the rules system is not "part of the game" it's little more than cheating. I like the skill the athletes bring to the table, and I respect guys who put everything out there like what happened today, but stupid flopping is stupid...