There's no basis for declaring it illegal. Its like saying that because you have a membership at Costco that everything in the store should be free. It doesn't work that way.

The networks produce the shows, the satellite and cable providers distribute them. Both expect and have a right to be paid for their services. Its a shitty system they've devised, with ads generating revenue to partially pay the networks, but the alternative to ads would be for the networks to demand more money from cable/satellite for distribution right and for the cable/satellite providers to demand MUCH higher subscription rates to offset it.