I am suggesting that buying something that has no worth is a bad idea no matter what organization you are. It's less a bad investment in the context of government and more a misappropriation of funds.
Government money represents hard earned cash of the people. The ability for the government to borrow -- its credit -- deals with its reputation as an entity that is capable of paying its debts. This reputation reflects on the people governed.
The people's money and its reputation should be respected. Money should be borrowed carefully to protect the people's reputation. Taxes should be spent wisely to protect and defend their purse. Wise expenditure is an important part of good stewardship, good government, and good politics.