These aren't people that operate within the law. They don't care and they frequently spoof numbers. They're also frequently calling from overseas using VOIP technologies so it costs them practically nothing.
The real reason these are so common? Because people are still so easily duped.
So how about instead of getting angry at a government program you don't understand you get angry it the idiots that keep allowing themselves to be fooled into these ridiculous scams? They're the ones that make it profitable enough to continue with this.