This is an "old man shakes fist at clouds" opinion, but I think HD video is a huge waste of time/money for living room watching. Your eyes cannot effectively resolve that resolution at normal "couch" viewing distances for common TV sizes. This is kind of like how audio quality peaked at CDish quality. Anything better is largely inaudible.
The key metric seems to be no longer how many users you can make sign up, but how can I keep an subscription running at lowest cost to serve possible.
The UHD price is not worth it for a long term subscription, and the HD quality is subpar.