Consider an analogy: let's say there's a power company who runs a monopoly on generating electricity. They also provide natural gas services to their customers. There is, however, a bunch of other smaller natural gas companies just a phone call away that people can buy natural gas from; all you have to do is call them and have a technician come and flip a switch in your home. Is it really harmful to the consumer if the power company with the dominant market position doesn't give their customers the phone numbers of the companies competing with its natural gas division? No.