When you "steal" a movie online, the studio only loses "potential" sales. Likewise, when you do (or do not) watch a movie, the resources used to produce the movie remain constant. When 100,000,000 people watch the same movie, the production costs of the movie to the studios are the same as if 10 people watch it. In otherwords, supply and demand does not apply when we have infinitely reproducible units of trade. You do not "steal" a movie, rather you "unfairly take advantage" of someone else's hard work. It's similar to the stolen valor act. You can't actually "steal" valor, but you can take credit for something you don't deserve credit for. Movies expected to "make more money" are given bigger budgets -- they have more "viewers" which distributes the production costs. Movies expected to make less money are given smaller budgets, and the distributed viewership shares the lower production cost of the movie. Finally, "gambles" are factored into other movies, so a movie that loses money is compensated for elsewhere.
It's not really "greed," if you're demanding to see the biggest explosions. If you want cheap movies go order a low budget foreign film online -- and you'll pay for the corresponding lower budget. Or, you know, stop watching movies. No one is twisting your arm to shell out $$$ on overpriced movies. If Hollywood loses enough viewers, they'll scale back production costs, until the average viewer feels the cost is worth it. As long as people shell out premium $$$, movies will have premium production costs. Big fat corporate greed problems don't apply to ridiculous luxuries like big budget movies. The MPAA is not "forcing" you to consume their products, and it won't hurt you one bit if you don't buy their stuff. If you expect them to lower their costs, as if you're entitled to that, then you're the one being greedy.