They don't chose their government in the sense they chose their doctor or internet provider. Obama is your president whether you like it or not. You are subject of the state and it's laws whether you like it or not. And you cannot opt out.

So, they don't chose their government, but they do trust it. Why?

a) Indoctrination, for the first 20 years of life. Would a teacher in a a state-sponsored and state-regulated schools / university teach you that state shouldn't be trusted?

b) Self-delusion. We can't live in an unjust world. Since we can't change the world, we change our world picture.
We persuade ourselves that state is not stationary bandit, but public servant. Not wolf, but shepherd.