If I buy tickets for Air Canada to fly somewhere and I miss my flight, it doesn't mean that WestJet should be free for the same route. If I buy tickets for a Blue Jays game and don't go the night my tickets are for, I don't have a right to that seat for the next game.
Again, what you're describing is a zero-sum game, which TV is not. Here's a different analogy: if you order a pizza at home, but you only eat half, should you be able to eat the rest at work the next day? The pizza company, given the choice, would say no, they would rather you buy a new pizza to eat at work. But of course that's ridiculous: you bought the pizza, why shouldn't you be able to eat it wherever you want?
However, what if you signed a contract saying that you would only eat the pizza at home, and in exchange the pizza company slightly discounted the pizza for you? Now, I think it would clearly be wrong to eat the pizza at home. But, what if the pizza company refuses to sell you pizza unless you sign that contract? And, they refuse to deliver the kind of pizza you want to your work under any circumstances? So now you've paid for a pizza which you can't eat under the current rules, and you can't legally get that pizza at work.
Look, there are many different angles to this. I think, for example, that it's clearly wrong to say that FX costs too much, and to pirate The Americans while refusing to subscribe to the channel because your cable bill is "high enough already." However, I'm not convinced that it's clearly wrong, if you pay for FX but The Americans airs at an inconvenient time, to download episodes and watch them at your convenience instead.