Why is it important for writers to plan their purpose for writing ?

It would help you manage your time. Now, some writers don’t, although sometimes it doesn’t always effect the writing. Sometimes it’s for manages times. It helps them remember that “hey, the topic is about this”. Some writers don’t need that reminder, but it certainly does help. It can help the writer actually finish the writing, making the writing not go on for too long by maintaining the topic. It really does help you not go off of the topic and makes the writer focus.