One factor in play is that many people only have experience with household-scale budgets. An intuition about what "millions" (let alone "billions") actually represents in terms of economic power is hazy at best. Business scale budgets sound extravagant; metropolis-scale or state-scale budgets are mind-boggling.

How does such a person know what's "too much"? Absent a reasonable working model of costs involved in infrastructure projects, it's all going to sound like too much.

And past a certain point on a spectrum of temperamental tendency to attribute laziness or wastefulness to other people, the working assumption is going to be it's boondoggles all the way down.

The only way to fix this -- if it can be fixed -- is reinforcing narratives about the value of projects and measured collective values.