Should ownership of newspapers be limited to mere millionaires? Or do you mean that private ownership of newspapers should be abolished?
This country was built on privately owned newspapers wielded as weapons by their owners; I'm sure you've heard of Benjamin Franklin. The First Ammendment protects this more than anything else for this reason.
Both can be true. I also consider it a failure of regulation and humanity that a billionaire can just own a newspaper and nix stories for clout.