The problem is how 'hard work' is defined. Does staying after hours count? Not automatically, but managers everywhere use it as a proxy ( whether it is dumb position or not is an argument in itself ). Does carefully considering your options count? Does being anal when it comes to minute detail count? All of these are small dimensions of hard work, but we throw those vague terms willy nilly, because we hope the audience will accept our 'used key term values' within our message to them.