No real reason? You don't count legislative pounding as a "real reason?"
When they're forced by law to allow you to pay down the highest interest balances first, for example, that radically changes their price structures, as does capping subprime card fees and interest rates for people with bad credit.
When you change the laws, for better or worse, the credit card companies are going to make adjustments to take those changes into account, usually by raising their interest rates.