The networks do charge for access to programming when they put it on the Internet, they just don't have to capture it from a broadcast.
Of course the networks charge consumers for cable/internet/satellite dish access. They license their programming to outside providers, or they themselves get into the (other than airwaves broadcast) transmission business, for which they charge a fee.
But that’s not my point. My point is the networks are not allowed to charge the American people for their BROADCAST signal. Aereo was charging for that, and that’s why the nets went to court.