The problem with credit cards, and the reason all young people should be advised to avoid them, is because it makes it a lot easier to spend money, and the easier it is spend money, the more you will spend.
Doesn't matter if you get 5% cash back or travel points - odds are, any money you "make" using a credit card will be more than offset by all the extra cash you spent because you use the credit card, as opposed to the more painful process of forking over cash.
The only exceptions to this rule are if you have expenses that are more or less fixed and unavoidable. For example, if you've got a job that requires a lot of travel, it's a great idea to charge that travel on a credit card with incentives. You don't have a choice to incur that expense, and you get reimbursed and get to rack up points.
But other than these few exceptions, the general rule holds true: you will save a lot more money using cash than you will "earn" using credit cards.
Yes, your life will probably be a lot more boring until you're rich at the age of 50 and get to retire. Then you'll laugh at all the assholes you preached about what a great deal credit cards are, and how what a great bargain those student loans are that they've been carrying around for the last 20 years.
/Dave Ramsey