Historically, government contracting and the public sector has been incredibly corrupt, as it's basically unlimited funds with no market-based mechanism to address it (in a private entity, the owners will be angry about money taken from their pockets by employees, and in places where corruption is too high, you end up with family firms or other external trust structures, very small entities, etc.)

This is why the heavy-handed regulations exist in US contracting (along with massive risk aversion and other things). The Government uniquely cannot be subject to market forces and punishment for bad actions.