While robocalls are annoying, what's the moral justification for making this illegal? If a person is allowed to call you, why can't a computer? Also the line is getting blurred recently, so it seems like a problematic distinction at this point in time.
It's mostly illegal to make human or automated marketing calls to numbers in the US that have signed up for the national Do Not Call registry. The problem is that huge numbers of illegal calls still reach numbers on the Do Not Call registry. Most of these illegal calls have no connection to any real business; they are instead trying to defraud people. I have often been called by "Microsoft Support" to alert me to Windows problems that need fixing. I don't have any Windows computers.