So, I don't know if this has been answered (I immediately started replying to your comment when I saw it in the thread), but the truth is... people who are diligent about how they utilize credit cards can, in fact, profit on them.
Similar to the way insurance companies work by hedging their bets that the majority of people won't get sick... credit card companies hedge their bets that the majority of folks will: a) carry a balance and pay high interest, b) miss payments and have to pay fees, c) generally not utilize their rewards programs well. Look up credit card churning sometime. There are people that make, literally, thousands of dollars or earn millions and millions of rewards miles by gaming the system that credit card companies have in place.
For every person that plays their cards right when it comes to credit cards, there are a handful of people that totally mess up and end up spending hundreds, if not thousands, in fees.
Read my other replies. We're talking past each other. I'm pointing out that the company has to pay for those rewards somehow, otherwise they go out of business. We call them a business and not a charity. somehow they are generating revenue to cover those rewards. And as I mentioned before, it's wise to read the fine print and your statements to figure out how the company is generating the revenue used for those rewards. If you can make it work, then great!
It very well may be the companies hedging their bets. Either way they will not do it without financial motivation.