People with a bad credit score tend to feel marginalized. They can't do everyday things like leasing a car, because car leasing companies refuse them. But now with credit cards to build credit they can revert their situations and start over. People with poor credit are sometimes grouped with those who lack of a credit history. If you have no credit score, then you should consider credit cards to build credit. Your whole life seems to be determined by your credit, so building it is important.
Credit cards to build credit help you fix your bad credit score or start it. You can find unsecured credit cards to build credit, that will provide you with a low credit limit, but as you prove to be regular with your payments, it may increase.