Why do idealists cry?

Some had been idiots as mad as Swing, with a view of the world just as rigid and unreal, who were on the side of what they called 'the people'. Vimes had spent his life on the streets, and had met decent men and fools and people who'd steal a penny from a blind beggar and people who performed silent miracles or desperate crimes every day behind the grubby windows of little houses, but he'd never met The People.

People on the side of The People always ended up disappointed, in any case. They found that The People tended not to be grateful or appreciative or forward-thinking or obedient. The People tended to be small-minded and conservative and not very clever and were even distrustful of cleverness. And so the children of the revolution were faced with the age-old problem: it wasn't that you had the wrong kind of government, which was obvious, but that you had the wrong kind of people.

As soon as you saw people as things to be measured, they didn't measure up....
Sir Samuel Vimes - Nightwatch by Terry Pratchet