I think a lot of the belief of government waste comes from anecdotal data usually centered around misunderstandings deliberate and otherwise. Welfare queens buying lobster (After not eating for a week). NASA bought a million dollar pen (It wasn't). People form opinions and ideas through stories. They see that there is a sub ten percent wastage and it doesn't even register. But tell a story about some insane thing the government did and people will remember it for decades.