I'm sure that you understand one of the basic rules of economics, that for an inflation to occur then the currency base must be expanding? Then if your experiencing inflation and economic growth, then someone somewhere is pumping a heap of money into your economy. Who? your Treasury is, Government Debt functions like money. So when your national debt is increasing, the monetary base of your economy is expanding.
There is some truth to this, in that the central Bank is required by law to consider government debt a high quality asset, and the commercial banks have the option to swap debt for cash if and when the central bank decides to expand the monetary base. In effect it's like the central bank prints money for the government's use, and the commercial banks are pocketing the interest.
That being said, you have to look at the magnitude of these operations to judge if govt. debt is merely a way of issuing fiat. As it turns out, in the case of the United States it's not: the Fed holds a quantity of bonds in the low trillions of dollars, while the total debt is in the order of 15 trillion of dollars. Roughly a third of that 15T is held by international lenders, a third is intergovernmental debt (pensions for federal employees, federal insurance schemes etc.), and another third is shared by the Fed and the general US public: mutual funds, private insurers etc.
So if you are an international entity that lent money to US or a pensioner, there's absolutely no "myth" of government debt: the US treasury actually owes you money, and it's very evil if they don't pay it pack. The other face of the evil is the captive citizens that are held accountable for debt they can't control, and which for the most part goes to finance actions that don't benefit them. Yup, govt. debt is pretty evil alright.