I'm most familiar with playwriting. My experience was that nearly every writer copies, panders (to the immediate opinion of their peers), and cognitively-herds

I'm most familiar with playwriting. My experience was that nearly every writer copies, panders (to the immediate opinion of their peers), and cognitively-herds like hell. They don't have a problem introducing superficial differences, they just have a problem being honest, authentic, or original - cause that might not please their peers instantly. They might not fit in. That's not just a local phenomenon, go read a book of short plays from the thirties, say, and nearly all will be trash for those reasons. Trash = not worth reading. (Lots of laughable interpretations of Freudianism, which was held in awe in artistic circles at the time, etc.) For me the advice boils down to: don't worry if your plays mention dogs or include cousins just 'cause a famous author's plays do too. Which is true advice, just not that useful in bringing into the Valhalla of real art. My advice would be: Do offend your peers and court their contempt. Almost no-one else will do this, so you can hardly help creating work that's original and which might survive with its reputation intact, which happens rarely with art.