I have to disagree with you. Creating a business based around something you believe in is arguably the #1 most powerful way to change the world.

Just because people make profit does not mean profit is their "only" goal. And like Paul Graham explained in his Y-combinator speech, there are certain services to humanity that simply would not work if they didn't make profit.

I think it's ridiculous to say that people like Steve Jobs are in it for profit. If Steve Jobs was after profit he would have been a highly successful wall street CEO or something. He does what he does out of personal ambition to improve the world. It's the same for 37signals and I would argue it's the same for Y-Combinator.