Question: Is "ought" the right word. Are there certain developments in popular culture that one is morally bound to be aware of?
Well, obviously not. Ignorance is no crime. On the other hand full participation in any community does rather require one to keep abreast of certain things that are going on in its culture. Corrie, Eastenders, Dr Who, Strictly, Dad's Army- knowing about these shows- even if you deplore them- is part of the freemasonry of being British. They're the esoterica we've been initiated into and foreigners mostly haven't. They bind us together. And the people who appear in them rank among our tribal totems. If I were to post a picture of Sir Bruce Forsyth here- which- perish the thought- I have no intention of doing- I'd expect every Brit on my friend's list to recognise him and every non-Brit (apart from one or two extreme Anglophiles) to go, "Who on earth is that weasel?"
Personally, I can't see the point of Bake Off, but I know who Nadiya Hussain is. I sort of feel it's my duty. "England expects..." and all that.