This is just pedantry completely ignoring the main point - of course, each tcp/ip connection sends bytes in both directions. But the connection to a residential customers (Netflix users) are very asymmetric - they are almost always initiated by user's initiative and have users request a lot of data flowing in their direction, while almost none flows in the opposite direction. It's not like Netflix just decides to send me a gigabyte of a movie. It's also not like we exchange gigabytes routinely in both directions. It's me asking to get the movie and paying for the privilege of getting it. The fact that technically a tiny stream of bytes also gets in other direction is irrelevant here.