It's all about the content.
UHD is good for certain types of documentary and for providing a distraction during boring bits of films/sport (e.g. counting the strands in the tennis net). When the content is sufficiently gripping, the resolution can go to hell. Something like Fritz Lang's 'M' is still a great viewing experience on an aged 405-line CRT. 'Big Brother' is shit even in whatever technology can manage in 100 years time.