I had to have a roof antenna because that was the only way to watch the 4 stations that were available. Cable offered a long list of stations and a clear picture. I can still watch over the air TV for free.
You take your argument too far. It isn't live TV that they are asking to be paid for. I agree that SNY has rights to their stream but I subscribe to YOUtube TV and I can tape anything they show. When SNY was on youtubetv I had a complete library of SNY games to watch whenever it suited me. It cost me nothing other than what I paid youtubetv. Cable DVR service allows taping of anything for replay later. So SNY was tacitly giving me permission to invite my friends over to watch their old games.
Furthermore, advertising is still a major source of revenue for all producers. Youtube asks extra money to not have ads to watch. SNY made a decision to raise their price and toutube tv said no and dropped them. Now, I'll bet that SNY's viewing audience has declined and as a result their ads cost less and their revenue has declined. (I watch foxsports now) and someone in their management is just being vindictive. They are perfectly within their rights as you say but why start now after allowing it for years? Weren't they losing revenue during the last 5-10 years?