I think 10% cap is a great idea. Many folks, including myself have been pushed to using cards for various reasons, unexpected healthcare, moving, home repairs, etc. Yes, we could do without some things that are convenience, like washing dishes by hand instead of fixing dishwasher.

The big thing for me is it's just wrong to charge 28%. I mean really? That is just usery and greed, and often gets many into a hole they can't get out of, just as you said. But really, what other industry or business has that kind of profit margin?
I remember back when checking accounts earned 6% interest and savings accounts earned 10% interest, and the credit card interest was less than that. How did this flip and such a wide gap difference occur? hmmm.