When the Avengers came out, I wanted to rent Captain America, Thor, and Iron Man 2 to watch before going to the movie. I couldn't do it. Blockbuster was out of stock of all 3, iTunes wouldn't rent them, but rather only sold them, they weren't on Netflix. I didn't want to buy them, I just wanted to watch them. I ended up not being able to watch them before we saw the Avengers despite driving around town and searching the various streaming rental sites. The movie industry lost money because of it.
See my post earlier in this thread: I was in the same situation as you, wanting to see those same three movies for the same reason. I did watch them on Netflix. No Iron Man 1, and no Incredible Hulk though.
Regardless, you still have made a great point. The movie industry loses out on revenue specifically because of their restrictive models. I know you rejected piracy as an acceptable alternative, but the fact remains that piracy thrives primarily because it's significantly less hassle. The studios should embrace the Netflix model if they seriously want to stamp out piracy. It's cheap enough that there's no reason to complain about the price, and it's much easier than torrents. For even the most picky viewer, the only missing ingredient is improving the selection.