But is this fair?
Certainly it seems fine to denigrate what is literally (literally) sado-sexual Twilight fan fiction, but from a purely grammatical standpoint, this might not be totally deserved.(Although from a storytelling/character development standpoint, well, again, it's Twilight fan fiction.)
But in the interest of fair play, the good folks at Grammarly have once again performed amazingly thorough research into the subject, and have provided this handy infographic to make all the stats easy for us to see. And the verdict is this: while you might find the characters drab and the plot lacking in substance, 50 Shades of Grey is no worse than many other classics when it comes to grammar, and indeed, is much better off than some.
This ultimately begs the question, is the real problem 50 Shades of Grey, or is it a publishing industry who has become lax about which books it chooses to print, and the quality of grammar that they institute in their releases? I say, let’s up our standards! The reading public will follow. So maybe grammarians in glass houses shouldn't throw stones.