Debt conversations always have these weird grandpa rules of thumb and words of wisdom, as you can see in the other comments. The proper use of debt is to match the debt with the asset. If you are buying a house, a 25-year mortgage matches the value of the house. If you are buying a car, a 5-year loan matches the value of the car. If you are buying a sandwich with a credit card, well... you should pay off your credit…
Were you deliberately using the "match the debt with the asset" rule of thumb as an example of your first sentence?
I was referring to "don't use any debt" and "debt is manifestation of risk" and "With great power comes great responsibility" and "use debt for investments, not expenses".