The demand for purity is at the root. She considers herself morally pure, perhaps, and doesn't see why others can't meet her standards.
Silly git. It's impossible.
Maybe she cant enjoy this pizza unless it's made by organically fed real Italians, with pure Italian ingredients and cooked in an authentic pizza oven? I'm pretty certain the answer is she'll eat pizza from her favourite place without questioning where they source their flour....
Does she refuse to wear clothing unless it's handwoven cotton from India, dyed with natural plant colours and stitched on a vintage hand crank machine whilst chickens cluck in the background? I bet she doesn't. I bet she buys clothes where she wants, same as the rest of us.
So why do authors have to be "pure"?