And yet it rings true. Sure, if everyone was a Mr. Smith it would be fine. But with poor incentive structures, people are collectively going to do what they have to do.

The same applies to police who aren't actively corrupt, but don't combat the corruption around them. The ones who do fight corruption end up fired 'with cause' at best, or forcibly committed to mental institution or killed at worst.

Used in the movie Wall Street to justify insider trading too:

Bud: Lou, I got a sure thing. Anacott Steel.

Lou: No such thing, except death and taxes. Not a good company any more. No fundamentals. What's goin' on, Bud? You know something? Remember, there are no short cuts, son. Quick-buck artists come and go with every bull market. The steady players make it through the bear markets. You're a part of something here, Bud. The money you make for people creates science and research jobs. Don't sell that out.

Bud: You're right, but you gotta get to the big time first, then you can do good things.

Lou: You can't get a little bit pregnant, son.

Bud: Lou, trust me. lt's a winner. Buy it.