Credit rating is an instrument of control used by banks and credit card organizations to force us into debt we don't want.
This system is CRAZY and I don't understand why normally anti-establishment and "leave me alone" Americans so sheepishly agree to be involved in a system that hurts our individual liberties every day.
When I came to this country the "credit score" system was the single most incomprehensible thing about american society. Still is.
When I came to the US from Europe, I had no credit history and that made it difficult to get any type of credit card, or loan, or anything. I thought it was a catch 22 since I couldn't build credit because I didn't have credit, but there is this thing called "Secured Credit Card", where the bank lends you your own money (that you deposit) to see if you can repay yourself. Had to do that for about a year, and I also managed to get a Macy's card with a $100 credit limit (yes, one hundred) that forced me to shop there to "build credit".
After that the climbing of the ladder started with credit limits increasing slowly, etc... up to the point that I was able to get a loan for a house.
There's a bit of strategic planning to building credit worthiness, and that requires you getting into some "managed debt". I think that was the spirit of the comment you are asking about.
A large part of the credit score concept is to flag people for whom paying a trivial bill on time is difficult.
Here you get full credit worthiness based on your income, savings and loans.
The income and (by tax proxy) savings are public, so no loans and some income and moderate savings will give you full credit.
Wait, how is that?
Because it's a private system, and it's at least theoretically voluntary. Nobody forces you to get credit cards or borrow money.
Credit cards are immensely convenient. I hardly ever carry cash anymore. I buy everything from coffee to lunch to groceries to gasoline using credit cards, and pay the balance every month. If I had to make arrangements to always carry cash to cover those sorts of expenses, it would be frustrating.
I've seen a slight increase in debit card rewards, like with Yelp, airline company dining rewards, and BoA rewards, but those are for the most part random and need to be planned spends. My credit cards will always reward me for using them.