Cable and TV networks pay for and buy rights to the movies (NBC for instance has access to the Universal Studios produceds films and already have permission from that studio), which for networks are edited at the movie studio for content and time constraints. This agreement in effect gives the TV stations permission to air the edited product.
Putting aside the copyright issue for a moment, you don't really find the artistic vision aspect of this debate compelling, do you? (Which is what the Hollywood libs are screaming about.) I think in that respect it is entirely hypocritical for Hollywood to whine about this. As I said in a previous post, the Directors and those actually involved with the making of the film usually aren't the ones making the decisions related to TV airtime. It's people who have no interest in maintaining artistic vision or integrity who make those decisions, and the decisons are based on money.
And I have purchased a right to watch the movie at home when I bought the DVD. How is sending that DVD to an edit company to make certain edits that I request in violation of that home viewing right?