Risks too great

Why is it accepted that government intervention is required when risk is high? The first "bailout" was a perfect example of this—the attitude was no private investors would buy certain securities at the current prices; therefore, government had to. But Hazlitt exposes this:

The proposal if frequently made that the government ought to assume the risks that are "too great for private industry." This means that bureaucrats should be permitted to take risks with the taxpayers' money that no one is willing to take with his own.