1. There is no question that stealing from the government should be a crime, and that the government (“malchus”) can criminalize such behavior. In a democratic country, one’s fellow citizens are also much annoyed when one steals from the government since that means you are stealing from your fellow taxpayers, who in a democracy, elect the government.
2. Many financial crimes involve disrupting markets, such as through cartels, insider trading, spreading misinformation, etc. These involve getting rich at the expense of others.
3. Whether prison is a useful penalty is questionable, but that’s a different issue.
4. It usually seems that being politically connected to those in charge helps one get away with all sorts of outrageous stuff – no hiddush in this matter.