In commercial societies, everybody wants you to buy their stuff.
Even though retailers lose a bit of their profit in their credit card fees, credit cards make it so easy to spend money painlessly and impulsively that, overall, they are a boon to retail commerce.
The average American received 15 credit card mail solicitations last year, so they're making plenty of money on this too. Good for them.
Spending discipline, thrift, saving, and "making do" are traditional American virtues, but, like so many valuable traditional virtues, they seem to be gradually going by the wayside in the face of our prosperity and growth. As David Brooks discusses, Seduction of borrowed money is making U.S. a nation of debtors.
The Frontal Cortex has a piece on Credit Cards and the Brain. Predictably, spending cash and spending via plastic have different impacts on the brain.
Financial suicide is painless. My rule is that all of my credit cards must be paid in full each month.