I always market research my books before I hand them in by showing them to five or six close friends who I trust to be honest with me, so they are very heavily re-written already.
You can have good writing, but a great actor will make it feel and sound like great writing. You can have great writing, and mediocre actors will make it feel mediocre. Without the actors, you have nothing.
Nowadays, the process of growth and development almost never seems to manage to create this subtle balance between the importance of the individual parts, and the coherence of the environment as a whole. One or the other always dominates.