Not sure I get that. A dollar spent is a dollar spent. If you're spending it on silly things, it doesn't matter if you're the government or private enterprise (who both sometimes spend their dollars on silly things).
A dollar spent is a dollar spent, but GDP is about production, not spending. If you spend a dollar for 1 iron nail or 1 dollar for 100 iron nails, it is not the same production even if by dollar measure it is the same value.
Governments are usually very inefficient. Corporations are also inefficient, but it is not the topic. The point is that we need to look more to the outcome than the money "value" because some governments made-up work has no value, but if you include it in GDP you inflate the GDP falsely.
