What he's trying to say is that most people crimes under the assumption that they won't get caught, not that, if they get caught, they can withstand the punishment.
While I agree that people conducting corporate fraud think they will get away with it - I don't agree that the long sentences won't act as a deterrence. If you set the sentence for these sorts of crimes to 1 year rather than 15+, that completely changes the risk profile for people who think there is a 90% chance they will get away with it.
Sentence length has a small effect on crime rates, but what really matters is enforcement levels. If you have a 99% chance of getting caught & punished, you don't bother.