The point is it's possible to be completely secure with bitcoins while credit cards are inherently vulnerable. And we are comparing apples and oranges. Bitcoin is a currency, credit cards are a service. You could, in theory, build a credit card company that deals in bitcoins. But why would you do that? There would be no advantage over just trading with bitcoins, and with bitcoins there is no chance of your credit card number getting stolen.

Someone can steal your bitcoins in the same way they can steal your physical cash.