I don't write or read much horror unless I fall into it sideways while sloshing around in my usual science fiction or fantasy. However, I love the British horror magazine Black Static. The magazine's editors and writers are always slicing their readers into bloody excellence, and the opinion pieces they publish are great beyond measure.
Case in point: Christopher Fowler's essay in Black Static 22 on "Why Mediocrity Rules." As Fowler states, he now actually hates the mainsteam. "Not because of who watches it – people will watch anything put in front of them – or who writes it – writers develop good ideas for years only to have them eviscerated or turned down outright because of passing fashions – but because of who decides what we watch and read."
As Fowler says, there are creativity killers in every profession, people who slink from position to position leaving "trails of destruction in their wakes, like snails." And while Fowler doesn't go into how the new media landscape of YouTube and Twitter and self-published ebooks are changing these trails of destruction, I haven't yet seen a ton of excellence rising to the top. Instead, when the "The Bed Intruder Song" receives 50 million views I'd say mediocrity has found new ways to thrive.
This doesn't mean every artist who whines about their lot in life deserves to be showered with praise. Fowler quotes John Cleese in his Monty Python architect sketch, when he delivers a slaughterhouse instead of a block of apartments and the clients complain. As Cleese says, "That’s the kind of blinkered philistine pig-ignorance I expect from you non-creative garbage." Not that Cleese should be allowed to build an abattoir to slaughter apartment dwellers. But the architect who eventually wins is in his own way worse than Cleese's character, and is praised for creating an absolute monstrosity.
I wish I could link to Fowler's essay; instead, I'll simply say you should subscribe to Black Static and that Fowler touches on some of these points in this recent blog post.