When someone bumps into you and you fall down in excruciating pain, shouldn't you leave the game? Happens in other sports all the time. In baseball, football, basketball, hockey, tennis, golf or any other sport I can think of here
To be fair, there's plenty of "flopping" in American sports, as well. I once saw Derek Jeter pretend to get hit by a pitch and get awarded first base. I constantly see NFL players fall to the ground after being nudged by an opposing player for the purpose of drawing a 15 yard penalty. And it's so bad in the NBA that they had to start fining the players this season (though Lebron always seems to get a pass).