I often write in poetry because it suits my aesthetic and my needs. But writing in general is cathartic. When the pain or emotions are so deep I can't get it out any other way - I write. My writing isn't for anyone else but me. This is especially true of my poetry, which tends to be pretty raw emotion and stays mainly untouched.
I hope by posting it here that it might touch someone else, speak to their needs, desires, emotions or fears. Help them on their journey. That would be amazing as well.