I was giving you a hard time. I don't think there's a significant percentage of people in finance for any reason other than money.
I am utterly fascinated with the capital markets and many aspects of finance. The returns reflect a true understanding of the markets. And yes, for the record, tech startups are in many ways less stressful than finance startups :)
As far as "altruism" is concerned, the value-add to society is wholly artificial: if our financial systems weren't structured to force retirement and pension funds to invest in the capital markets, I highly doubt anyone would say they were doing something good for the world.
You must think Steve Jobs has spent the last few years working at Apple, when he probably should have been doing something less stressful, because he wants yet another billion dollars?