Horseshit. Most individuals and most private firms pay their debts.
Where did I say they don't? You seem to think that paying debt is incompatible with monetizing debt. If you borrow $100,000 to start a business, aren't you monetizing that debt? Don't you have to recoup that debt, plus more, in order for your business to be successful?
Let's say that I currently have $50,000 invested with T Rowe Price or some similar company. I get an average yearly return of at least 12 percent. My car reaches its final leg and I need to buy a new one. I pick something out that will cost $25,000. Now, I could easily pull money out of my investments and write a check for the 25 large. But the better option would be to take out a car loan and pay 5% interest on the loan. That way, I can keep the $25k invested, and returning 12% or more to me. By doing so, I'm monetizing the car loan, allowing me to make more money than if I hadn't taken out the loan. I can make every single payment on time and repay every penny, but I'm still monetizing my debt.
The government is monetizing debt in pretty much the same way. Government spending contributes to economic growth, but comes at the cost of the need to repay the debt with accrued interest. Currently, economic growth outpaces the rate of interest, thus creating the phenomenon of negative interest. It's a net gain for the American economy.