Whew, back from Paris.
Well, people as a group can be surprising. Popularity is just that, something having a large mass appeal; and familiarity is the watchword when it comes to big things, especially since film and TV are typically hard to create to a high standard so sequels and so forth currently are safer bets.
Slowly it is improving mind you; accessibility is an issue so even lower key films (which may be surprisingly popular) get bigger releases over just arthouse cinemas, and TV shows get their iPlayer downloads made available so popularity of poorly-timed shows increases. Without getting access to the more original titles, it is hard to judge how much people like them - after all is my statement above just a self-fulfilling prophecy? That they get money from sequels because they create them incessantly?
(In fact me being cynical and actually based on mucho data, it is mainly marketing which determines box office results, and for TV a mixture of marketing and slot timing - ie; people always watch TV at a certain peak time so things on then are, well, popular! again...self fulfilling prophecy and all that. Anime and other more foreign or low key things never reach the peak of "common popularity" I think to have this be in effect though - ie; marketing is non-existent, and accessibility is an issue).
Of course poor critics, reviewers and others just declare things as original without really checking (I am sure even simple searching the internet for things based off Romeo and Juliet you'd find this!). That can be another issue of course
