Yeah, given the prices even buying digital content is a dodgy proposition for what you end up getting, but renting is a fools game if you ask me. Say you want to sit down and watch a season of Big Bang Theory (something I did very recently). It would cost you roughly $23.00 and 24 hours later it's gone. Poof.
That would just make me feel like an idiot, which I can actually do for free. I don't need to pay the media companies to feel bad.
IMO it should be more like 99 cents an episode to buy it, not rent it.
(in fact it's $60.00!)
And you re-watch TV shows... how often?
Most TV content is disposable. Building a business model on buying it is silly.
Most quality content (HBO, PBS, etc) is usually available eventually for purchase.