I had low expectations for the new Apple TV, and this is one of the signs (combined with my theory that "apps" are not what people want on their TV anyway). Chromecast already did authentication right; how are they still so far behind?  (Also, just check out that onscreen keyboard layout.  Absolutely user-hostile, and vastly worse than the old Apple TV.)

https://medium.com/@bdotdub/signing-into-apps-on-apple-tv-sucks-d36fd00e6712