Greed isn't necessarily bad. If it means figuring out what service millions of people will pay money for, then yes, you're making money. but you're also creating a useful service. The two often go hand in hand.
Creating a good product because your greed says it will get you more money is ok, but I think the point is that if you flip it round - create a good product because you want your product to be good - you get a better product and potentially more money.