The advantage to the company with rewards is they get to keep your money while you think about how to spend it and you might never spend it. See gift cards & book tokens too, what a scam.
Right now, the bank that issued my credit card has just under $2000 worth of accumulated rewards that I haven't gone to push the buttons to convert to cash in my account.
If I'd consistently used a debit card instead to make those purchases, there wouldn't be any such balance, but I also wouldn't have any more money either.
I don't quite see this as being something where I should change my behavior in order to avoid this "scam".
One good thing that came from this thread is I went to my bank's website, clicked a few buttons, and $1990 is being converted from rewards points to cash that will hit my account next week. They really got me on that scam and I hope they'll get me again every couple of years.
Or, you know they could just pay it in without you doing anything. While that's sitting there as rewards you don't get interest on it but they can still use it.