tl;dr: 'Elites' (or at least those to be found in Who's Who) now prefer to affect a taste for 'ordinariness' instead of preferring high culture or horsey pursuits.
That's one interpretation. It might also be that having a "normal" life with pets, vacations and cupcakes is sufficiently difficult for regular people today that instagramming about it is elite enough.
Not to mention the Jarvis Cocker fascination: https://www.youtube.com/watch?v=dxhQiiNJG74