Why did Rod Blagojevich get 14 years for doing what all politicians do?

What dillusion creates the notion that politicians are not generally corrupt, narcissistic, ambitious, amoral bozos?
The whole notion of civil politics exists in order to give these creeps a niche where they can go do their dirty work as far removed as possible- somewhere, anywhere but next door to you and me.
The American founders had the good sense to organize a government where the chances of them doing real damage to you and me were minimized.
Occasionally, they get sloppy, and we discover what we already knew, but simply did not want to talk about. They are losers, criminals in a dark suit and red tie, wolves in sheep’s clothing so to speak.
So we, as if we were shocked and surprised, toss them in prison for 14 years, or worse,in order to express our feigned outrage. Like the guy in the movie Casablanca-“I am shocked, SHOCKED, to find gambling in here!”
As if we are surprised to discover what most people know to be true in the first place.
Isn’t that a little disengenuous on “our” part?