As a free verse poem is not limited by regular meter or rhythm, a poet can fully express himself in the same way. There is nothing between him and his artistic expression. Rhyme scheme rules can't hold his creativity and imagination. Beauty of writing can still be expressed using pauses and natural rhytmical phrases. Sometimes accepted rules and norms in society make us feel caged, getting rid of those barriers can help us express our full humanity. This is a good way for a poet to do so.