It doesn't matter how much the MPAA costs in relation to current levels of BitTorrent traffic. The comparison you need to make is the cost of the MPAA vs. the amount of money Hollywood made from Netflix. From the MPAA's perspective, if there was unfettered piracy and no making/enforcement of the laws, everyone would pirate their content. Thus, the MPAA is protecting the $180 billion that Hollywood made off Netflix because those customers did not steal.

Now obviously lawsuits and lobbying drive some customers to choose Netflix over BitTorrent, but there's also the fact that Netflix and BitTorrent deliver completely different online movie services. Netflix serves customers a limited selection of movies that they can start watching right now. BitTorrent delivers "customers" any movie they want, but they need to wait before they can start watching it the first time. They can watch it right away any time after that, even if they aren't on the internet, however. The author assumes that, cost aside, Netflix provides a superior offering. That might be true, but if both were legal, I know what I would choose (and it's not Netflix).