America does bear the tarnish of Stephanie Meyer, but we can also claim Jonathan Franzen, Donna Tartt, Annie Proulx, Dave Eggers, etc. And while the UK has Martin Amis and Ian McEwan, you've also got Freya North and her like. There are high brow and low brow writers in all cultures. There are not more low brow writers proportionally speaking in the USA than there are in the UK.

And the movies mindless disaster movies that tend to do well in the US tend to do well over here too. *cries over the death of the wonderful British film industry that was so alive and thriving when I arrived here, but is now not much more than dead*

The dumbing down of culture is a universal problem. It's not specific to Americans.