Piracy = popularity. The big studios take torrent popularity as a metric these days. Even if you're not paying for the show, everyone seeding and downloading that torrent is being used as a sign by the industry that they should keep giving Rowling money which she, in turn, uses to harm people.

Pirating her content is still making her rich, while also granting her a deeper foothold in your own media environment, heart, and mind. You deserve better, and you can do better.