Or, lots of people aren't taught properly how to use things like credit cards, investments, etc. They have to learn it themselves.
My first run in with credit debt, and an eye opening one, was when my parents gave me a card to use while I was in college. I was told to use it for clothes, cheap furniture, light bulbs, parking fees--anything not covered by my tuition or what I was earning at my part time job ( food and books). I used it sparingly for these things.
After four years, I graduated in 1992. My parents proudly handed me my credit card bill of $3000.. Because they had been making minimum payments.
I worked hard to run that debt down to zero, and learned 1) don't carry a balance, 2) use sparingly, 3) it's really easy to run up debt if you only make minimum payments.
Oddly enough, it also gave me a basic credit score because they never missed a payment!