>Because there are laws prohibiting exactly what he did. It's really that simple.
Ok, but that's just an appeal to authority, what's the moral grounding for those laws?
Of course lying and being deceitful for personal gain is wrong but why is it a criminal matter when an individual does it but a civil matter when a group does it?
There are laws against doing a thing, he did the thing and got caught. Go to jail, do not cross Go, give back the $500,000.