In order of importance:
Trading is challenging
Trading is my pastime
Work and live anywhere
Help me avoid the rat race/politics in business
Trading is easier than doing other jobs
Possibly the best is that I have no boss, no customers, no inventory, no selling, none of the hassles that are involved in just about every business one can own. Just today I was thinking about all the stupid decisions my previous managers have made, things like canceling flex time and instituting a dress code (O/E Systems), promoting a bunch of incompetent babes to management (Microsoft), hiring an idiot for a fortune then sending him out to ruin the milk cow project (Pathway Systems), the list is endless.
Now I just laugh. They are free to ruin their companies, and it does not impact me. They can implement the most ludicrous 97 page reporting requirements, 25 hour weekly meetings, 250 word mission statements all they want, and it has no effect on me. And that makes me smile. So I don't think that is part of the "avoid the rat race" answer, but it is a major part of why I trade. Because when I trade, the idiots make money for me, instead of adding misery to my life as in the corporate world.