It's not really fair to say such a general statement, because clearly some of them do, sometimes the market won't stay irrational (or it will work irrationally in your favor) for too long, etc.

However, focusing on creating value is a much more sure bet and more rewarding in the end. I don't want to go off in a long tangent in what will likely be a dead thread, but years of playing poker for a living really taught me this lesson.

The truly happy people I know all create tremendous amounts of value. While most of them aren't 'rich' they definitely live lives of abundance.