What came first? Prose or poetry? The romantic part of ourselves might like to believe that poetry came first. However, Steven Pinker suspects prose did: The earliest writing systems seemed to involve very mundane matters, like which farmer stored how much grain of what kind in the granary. It seems that writing started off as a kind of record keeping for agricultural surpluses before it was expanded to all of the various messages that we enjoy today. Why is poetry special? We recognise that poetry is a very special kind of speech. It tends to be used in special occasions, for a particular purpose of arousing an emotional reaction in people.
You can recognise poetry in languages you don't speak. You can even recognise poetry in sign language.
Poetry is special and it suggests that it builds on top of abilities that we use much more as we say prosaically, namely for prose. What is good writing? There isn't one answer to that question because people write for different purposes.
People write to arouse emotions in their listeners, they write to get complex ideas across, they write to create a sense of solidarity with their readers.
What allows them to accomplish those tasks is going to vary depending on what the task is.
Good writing: considers its audience. respects the reader's short-term memory. never strays too far from speech.